ModuleWrapper.gmk doesn't consult include path

A change made to ModuleWrapper.gmk as part of JDK-8244044 means that an included makefile is found in the current directory, so Make doesn't check the include dirs for overriding gmk files.

Recommend a minor, partial reversion of this changeset to ensure any override files are included instead.

https://github.com/openjdk/jdk/pull/250