NIFI-4388: Modules Not Honored

[bdesert]

Modules aren't honored. The bug is not reproducible in Jython (it handles modules with every script reload). But Groovy loads JARs and dirs with classes only on setup. Cannot provide test cases for Groovy, because it requires custom JARs to be provided as part of the package.

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[mattyb149]

+1 LGTM, tested the fix and verified the modules are now being reloaded upon property value change. Thanks for the fix! Merging to master