Fixed parallel pool creation error on start up

[Danil20-8]

System.AggregateException : One or more errors occurred. (An item with the same key has already been added. Key: server=db;port=3306;user id=u-poolingtes-0;persistsecurityinfo=True;allowuservariables=True;pooling=True;connectiontimeout=600;database=db-poolingtes-0;password=pwd;minpoolsize=10)
   ----> System.ArgumentException : An item with the same key has already been added. Key: server=db;port=3306;user id=u-poolingtes-0;persistsecurityinfo=True;allowuservariables=True;pooling=True;connectiontimeout=600;database=db-poolingtes-0;password=pwd;minpoolsize=10
   Stack Trace:
      at System.Linq.Parallel.QueryTaskGroupState.QueryEnd(Boolean userInitiatedDispose)
    at System.Linq.Parallel.SpoolingTask.SpoolForAll[TInputOutput,TIgnoreKey](QueryTaskGroupState groupState, PartitionedStream`2 partitions, TaskScheduler taskScheduler)
    at System.Linq.Parallel.DefaultMergeHelper`2.System.Linq.Parallel.IMergeHelper<TInputOutput>.Execute()
    at System.Linq.Parallel.MergeExecutor`1.Execute()
    at System.Linq.Parallel.MergeExecutor`1.Execute[TKey](PartitionedStream`2 partitions, Boolean ignoreOutput, ParallelMergeOptions options, TaskScheduler taskScheduler, Boolean isOrdered, CancellationState cancellationState, Int32 queryId)
    at System.Linq.Parallel.PartitionedStreamMerger`1.Receive[TKey](PartitionedStream`2 partitionedStream)
    at System.Linq.Parallel.ForAllOperator`1.WrapPartitionedStream[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings)
    at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream)
    at System.Linq.Parallel.ScanQueryOperator`1.ScanEnumerableQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient)
    at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient)
    at System.Linq.Parallel.QueryOperator`1.GetOpenedEnumerator(Nullable`1 mergeOptions, Boolean suppressOrder, Boolean forEffect, QuerySettings querySettings)
    at System.Linq.Parallel.ForAllOperator`1.RunSynchronously()
    at MySql.Data.MySqlClient.Tests.PoolingTests.BasicConnection() in /app/MySQL.Data/tests/MySql.Data.Tests/PoolingTests.cs:line 51
    at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
    at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr)
 --ArgumentException
    at System.Collections.Generic.Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
    at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
    at MySql.Data.MySqlClient.MySqlPoolManager.GetPoolAsync(MySqlConnectionStringBuilder settings, Boolean execAsync, CancellationToken cancellationToken) in /app/MySQL.Data/src/MySqlPoolManager.cs:line 149
    at MySql.Data.MySqlClient.MySqlConnection.OpenAsync(Boolean execAsync, CancellationToken cancellationToken) in /app/MySQL.Data/src/MySqlConnection.cs:line 650
    at MySql.Data.MySqlClient.MySqlConnection.Open() in /app/MySQL.Data/src/MySqlConnection.cs:line 581
    at MySql.Data.MySqlClient.Tests.PoolingTests.<BasicConnection>b__1_0(Int32 _) in /app/MySQL.Data/tests/MySql.Data.Tests/PoolingTests.cs:line 56
    at System.Linq.Parallel.ForAllOperator`1.ForAllEnumerator`1.MoveNext(TInput& currentElement, Int32& currentKey)
    at System.Linq.Parallel.ForAllSpoolingTask`2.SpoolingWork()
    at System.Linq.Parallel.SpoolingTaskBase.Work()
    at System.Linq.Parallel.QueryTask.BaseWork(Object unused)
    at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
 --- End of stack trace from previous location ---
    at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
    at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

[mysql-oca-bot]

Hi, thank you for submitting this pull request. In order to consider your code we need you to sign the Oracle Contribution Agreement (OCA). Please review the details and follow the instructions at https://oca.opensource.oracle.com/
Please make sure to include your MySQL bug system user (email) in the returned form.
Thanks

[Danil20-8]

There is something broken on https://oca.opensource.oracle.com/

I can't access it

[mysql-admin]

Hi @Danil20-8
Maybe there was a temporary issue - I can access it now without an issue

Thanks
==Omer

[Danil20-8]

That is the error i'm still getting

[Danil20-8]

So, it has been opened over vpn. Probably the site is blocking me.

[mysql-oca-bot]

Hi, there was no response to our request to sign an OCA or confirm the code is submitted under the terms of the OCA. As such this request will be closed.
Thanks