glx: Add missing glproto dependency for gallium-xlib glx

Cc: mesa-stable@lists.freedesktop.org
Cc: Bruce Cherniak <bruce.cherniak@intel.com>
Signed-of-by: Chuck Atkins <chuck.atkins@kitware.com>
Reviewed-by: Bruce Cherniak <bruce.cherniak@intel.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/configure.ac b/configure.ac
index 49c5e25..bc92fb5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1598,6 +1598,9 @@
 dnl
 dnl libGL configuration per driver
 dnl
+if test "x$enable_glx" != xno; then
+    PKG_CHECK_MODULES([GLPROTO], [glproto >= $GLPROTO_REQUIRED])
+fi
 case "x$enable_glx" in
 xxlib | xgallium-xlib)
     # Xlib-based GLX
@@ -1611,7 +1614,6 @@
     ;;
 xdri)
     # DRI-based GLX
-    PKG_CHECK_MODULES([GLPROTO], [glproto >= $GLPROTO_REQUIRED])
 
     # find the DRI deps for libGL
     dri_modules="x11 xext xdamage xfixes x11-xcb xcb xcb-glx >= $XCBGLX_REQUIRED"