FIx acctdb unit test

[ryanrdoherty]

Broken unit test assigning DatabaseInstance using mock/reflection

DbManagerTest > getAccountDatabaseNotExists() PASSED

DbManagerTest > getAccountDatabaseExists() FAILED
    java.lang.IllegalArgumentException: Can not set org.veupathdb.lib.container.jaxrs.utils.db.DatabaseInstance field org.veupathdb.lib.container.jaxrs.utils.db.DbManager.acctDb to org.gusdb.fgputil.db.pool.DatabaseInstance
        at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
        at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
        at java.base/jdk.internal.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
        at java.base/java.lang.reflect.Field.set(Field.java:799)
        at org.veupathdb.lib.container.jaxrs.utils.db.DbManagerTest.getAccountDatabaseExists(DbManagerTest.java:28)

I think it may have to do with JDK versions used in compilation, but that is just a guess. Able to publish with this broken test so leaving as an issue.