Libnotify depends on gtk, but leaves the choice between gtk2 and gtk3 to the calling application.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
(cherry picked from commit f62e6d6e7ca732471f84fc766988553974b8a1b8)

configure.ac

@@ -1721,7 +1721,7 @@ AS_IF([test "${enable_growl}" != "no"], [
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 dnl Libnotify notification plugin
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-PKG_ENABLE_MODULES_VLC([NOTIFY], [], [libnotify], [libnotify notification], [auto])
+PKG_ENABLE_MODULES_VLC([NOTIFY], [], [libnotify gtk+-2.0], [libnotify notification], [auto])
 
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 dnl Taglibplugin