scripts: libwebkitgtk is not shiped in a gtk2 version anymore, had to ajust the count

scripts/casper-remove-needed-packages-from-unistall-manifest.awk

@@ -2,7 +2,7 @@
 
 BEGIN {
 	# This is the number of things we're going to remove. Adjust it when changing the regular expression below
-	want = 6;
+	want = 5;
 	skipped = 0;
 }