www/cliqz: Fixes build failures under certain conditions.

• Redo the MOZ_CONFIGURE_ARGS so that port options picks it up correctly.
• Adds check for libmozwayland.so (available when x11-toolkits/gtk30 is built with WAYLAND option enabled).
• Drops a patch hunk not applicable to patch-bug847568 (reported by jbeich@).

Approved by: philip (mentor)