Revert "NEXUS-5863: Attribute recursion caused by OS native path separator"

This reverts commit bcac2448b5ea57c6bb09dcfc878fe49ff2ac7a75.

move the very same fix into RubygemsFile class
moved fix from commit bcac2448b5ea57c6bb09dcfc878fe49ff2ac7a75 into RubygemsFile class along with
similar path adjustments