Revert "Revert "Simplify ScroogeGen.""

This reverts commit e95ccc94b7c511101bd37ea09a473ca038963d22.
Remove a broken line in ScroogeGen that was overlooked.
Sync of https://github.com/pantsbuild/pants/commit/266f7e9d28f3f1ed19bf96cb2b7693616807bd3f