try fix sym_channel table from altering each time (mysql)

symmetric-core/src/main/resources/symmetric-schema.xml

@@ -43,7 +43,7 @@
         <column name="data_loader_type" type="VARCHAR" size="50" required="true" default="default" description="Identify the type of data loader this channel should use.  Allows for the default dataloader to be swapped out via configuration for more efficient platform specific data loaders."/>
         <column name="description" type="VARCHAR" size="255" description="Description on the type of data carried in this channel."/>
         <column name="queue" type="VARCHAR" size="25" default="default" required="true" description="User provided queue name for channel to operate on.  Creates multi-threaded channels.  Defaults to 'default' thread"/>
-        <column name="max_network_kbps" type="DECIMAL" size="10,3" default="0" required="true" description="The maximum network transfer rate in kilobytes per second.  Zero or negative means unlimited.  When throttling the channel, make sure the channel is on its own queue or within a queue of channels that are throttled at the same rate.  This is currently only implemented when staging is enabled."/>
+        <column name="max_network_kbps" type="DECIMAL" size="10,3" default="0.000" required="true" description="The maximum network transfer rate in kilobytes per second.  Zero or negative means unlimited.  When throttling the channel, make sure the channel is on its own queue or within a queue of channels that are throttled at the same rate.  This is currently only implemented when staging is enabled."/>
         <column name="create_time" type="TIMESTAMP" description="Timestamp when this entry was created." />
         <column name="last_update_by" type="VARCHAR" size="50"  description="The user who last updated this entry." />
         <column name="last_update_time" type="TIMESTAMP" description="Timestamp when a user last updated this entry." />