lookingGlass: Don't include telepathy import by default

It's hardly a common include nowadays, and removing it keeps all
telepathy usage contained in the telepathyClient component.

https://bugzilla.gnome.org/show_bug.cgi?id=779878

js/ui/lookingGlass.js

@@ -33,7 +33,6 @@ var commandHeader = 'const Clutter = imports.gi.Clutter; ' +
                     'const Mainloop = imports.mainloop; ' +
                     'const Meta = imports.gi.Meta; ' +
                     'const Shell = imports.gi.Shell; ' +
-                    'const Tp = imports.gi.TelepathyGLib; ' +
                     'const Main = imports.ui.main; ' +
                     'const Lang = imports.lang; ' +
                     'const Tweener = imports.ui.tweener; ' +