Fix building of qt4 gui

configure.ac

@@ -5156,7 +5156,7 @@ AS_IF([test "${enable_qt4}" != "no" &&
       AC_DEFINE([HAVE_QT4], 1, [Define to 1 if you have QT4 library.])
       ALIASES="${ALIASES} qvlc"
       enableqt4=true
-      VLC_ADD_LIBS([qt4],[$QT4_LIBS])
+      VLC_ADD_LIBS([qt4],[$QT4_LIBS -lX11])
       VLC_ADD_CXXFLAGS([qt4],[$QT4_CFLAGS -DQT4LOCALEDIR=\\\\\\\"$($PKG_CONFIG --variable=prefix QtCore)/share/qt4/translations/\\\\\\\"])
       AC_PATH_PROGS(MOC, [moc-qt4 moc], moc,`$PKG_CONFIG --variable=exec_prefix QtCore`/bin)
       AC_PATH_PROG(RCC, rcc, rcc,`$PKG_CONFIG --variable=exec_prefix QtCore`/bin)