Remove MaxPermSize=256m VM arg from Window product

MaxPermSize=256m VM argument is used in the product launcher configuration. This argument doesn’t exist anymore in Java 1.8, producing this warning:

Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0

1. determine why this argument has been added
2. remove it of find an equivalent if needed

(from redmine: issue id 2681, created on 2019/11/29 by Sebastien Jacquot)