Inaccurate warning message when changing editor settings on Linux

When making changes to Editor Preferences or Project Settings on Linux, a warning message appears that the ini file is not writeable, however the changes are still recognized/saved.

This warning message does not appear on Windows (tested binary and github source)

1. Open UE4 Editor (any project)
2. Open Editor Preferences->General->Appearance->User Interface
3. Check box for "Use Small Tool Bar Icons"

Result:
Message appears about EditorPerProjectUserSettings.ini not being writeable

Expected:
Settings are changed without warning message appearing.