Fix random failure of ModuleActivatorTest

This unit test passes and fails randomly:
shouldStopDependantModulesOnStopModule(org.openmrs.module.ModuleActivatorTest)

We need to fix it such that it passes all the time.

After fixing this, remove the @Ignore in:
master at: https://github.com/openmrs/openmrs-core/commit/8155a771f2a5aed52078eca21ac2f8382f36ab08
1.11.x at: https://github.com/openmrs/openmrs-core/commit/1cd7d08e13fb67a210b4459a51e28ac887be757a
1.10.x at: https://github.com/openmrs/openmrs-core/commit/0aaf8e6e09b1302403aec877ef5f6ca0533220e7