Revert "Disable swscale if avcodec is disabled" because the swscale doesn't...

Revert "Disable swscale if avcodec is disabled" because the swscale doesn't need it anymore since [5f919fba]

This reverts commit 964c7e91.
Please, do NOT backport this.

configure.ac

@@ -2768,9 +2768,7 @@ dnl
 
 AC_ARG_ENABLE(swscale,
   AS_HELP_STRING([--enable-swscale],[libswscale image scaling and conversion
-		  (default enabled)]),, [
-  enable_swscale="${have_avcodec}"
-])
+		  (default enabled)]))
 if test "${enable_swscale}" != "no"
 then
   PKG_CHECK_MODULES(SWSCALE,[libswscale],