Remove obsolete plural forms if exist in PO file
Remove obsolete plural forms if exist in PO file

participedia/pontoon,mozilla/pontoon,yfdyh000/pontoon,Osmose/pontoon,jotes/pontoon,sudheesh001/pontoon,m8ttyB/pontoon,jotes/pontoon,m8ttyB/pontoon,Jobava/mirror-pontoon,mozilla/pontoon,participedia/pontoon,mozilla/pontoon,vivekanand1101/pontoon,yfdyh000/pontoon,sudheesh001/pontoon,Jobava/mirror-pontoon,yfdyh000/pontoon,Osmose/pontoon,jotes/pontoon,mathjazz/pontoon,mathjazz/pontoon,participedia/pontoon,vivekanand1101/pontoon,vivekanand1101/pontoon,vivekanand1101/pontoon,m8ttyB/pontoon,mastizada/pontoon,mozilla/pontoon,mastizada/pontoon,Jobava/mirror-pontoon,mastizada/pontoon,sudheesh001/pontoon,m8ttyB/pontoon,mathjazz/pontoon,participedia/pontoon,sudheesh001/pontoon,Osmose/pontoon,Jobava/mirror-pontoon,mathjazz/pontoon,mastizada/pontoon,mozilla/pontoon,mathjazz/pontoon,Osmose/pontoon,jotes/pontoon,yfdyh000/pontoon