NIFI-3222 - Allow ExecuteScript to use ExpressionLanguage to define …

[trixpan]

…the scripting engine modules path

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[trixpan]

@mattyb149 Would you be able to give me a hand with this PR?

Cheers!

[mattyb149]

Code LGTM, my comments would be to add this same improvement to InvokeScriptedProcessor, and update one unit test apiece to use Expression Language to set the Module Directory property, to prove that this works

[trixpan]

fair enough. will do both

[mattyb149]

And there's a typo in Language in the commit/PR title ;)

[trixpan]

@mattyb149 - should be all goody now

[mattyb149]

+1 LGTM, Built and ran unit tests, ran NiFi with ExecuteScript using EL for Module Directory, everything looks good. Thanks much for the improvement! Merging to master