gnu: clementine: Drop dependency on qtwebkit.

QtWebkit is optionally included in CMakeList.txt but isn't actually used
anywhere in the code.

* gnu/packages/music.scm (clementine)[inputs]: Remove qtwebkit.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu/packages/music.scm

@@ -281,7 +281,6 @@ score, keyboard, guitar, drum and controller views.")
          ("pulseaudio" ,pulseaudio)
          ("qtbase" ,qtbase)
          ("qtx11extras" ,qtx11extras)
-         ("qtwebkit" ,qtwebkit)
          ("sqlite" ,sqlite-with-fts3)
          ("sparsehash" ,sparsehash)
          ("taglib" ,taglib)))