pidgin/pidgin

Remove the gtk-dnd-hints stuff that should have been removed when we removed dnd from the conversation window.

Testing Done:
Compiled.

Reviewed at https://reviews.imfreedom.org/r/1098/
[Desktop Entry]
Name=Pidgin
GenericName=Internet Messenger
Comment=Chat over IM. Supports Jabber/XMPP, and more
Exec=purple3-url-handler %u
TryExec=purple3-url-handler
Icon=pidgin
StartupNotify=false
Terminal=false
NoDisplay=true
Type=Application
Categories=Network;InstantMessaging;RemoteAccess;ConsoleOnly;
MimeType=x-scheme-handler/gg;x-scheme-handler/irc;x-scheme-handler/sip;x-scheme-handler/xmpp;
@USES_MM_CHAT_SECTION@