Fix "Error in file "/usr/share/applications/SkEditor.desktop": "Version=2.7.1-prerelease" is an invalid MIME type ("Version=2.7.1-prerelease" does not contain a subtype)"

Fix "Error in file "/usr/share/applications/SkEditor.desktop": "Version=2.7.1-prerelease" is an invalid MIME type ("Version=2.7.1-prerelease" does not contain a subtype)" #13