Prefer the local version of x11spice when running locally.

Fixes a bug introduced by the 1.2 script change.
Acked-by: Frediano Ziglio <fziglio@redhat.com>

spice-video-dummy/spicedummy.sh

@@ -79,9 +79,9 @@ else
     xorg=`which Xorg`
 fi
 xmodules=`"$xorg" -showDefaultModulePath 2>&1`
-x11spice=`which x11spice`
+x11spice="$dummydir/../src/x11spice"
 if [ ! -x "$x11spice" ] ; then
-    x11spice="$dummydir/../src/x11spice"
+    x11spice=`which x11spice`
 fi
 
 if [ ! -x "$x11spice" ] ; then