Update telugu nplurals

Summary: We set it to nplurals=5 back then because it was what the KDE translation was using, but after talking to the new people that are taking care of telugu in KDE and checking with other translation teams (gnome, etc) we have no idea where the 5 was coming from, so switch to 2

Reviewers: sdepiets

Reviewed By: sdepiets

Subscribers: ltoscano, sdepiets

Differential Revision: https://phabricator.kde.org/D19716