utils: cleanup: LocalConfig: fix defect: Found reliance on default encoding: new java.io.FileReader(File)

Funny! This object, FileReader, does not support encoding while its base
class does.

Change-Id: I89b4009f37256110a10b97b1d1c1b273b07e6a86
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>