Config Script: explicit "indy" setting is overridden by project sensing "indy" from core jar

[eric-milles]

Given a Groovy project with "indy" flavor of core library (Groovy 2.5+ in Groovy Libraries for example), if the "indy" optimization option is explicitly disabled in a compiler config script, that preference is overwritten by the automatic detection of "indy". User's explicit setting should take precedence.