Fix include path

We already use pkg-config in configure for the fist part
(cherry picked from commit a985ebd5)
Signed-off-by: Christophe Mutricy <xtophe@videolan.org>

modules/misc/svg.c

@@ -48,7 +48,7 @@
 #include <glib.h>
 #include <glib/gstdio.h>
 #include <glib-object.h>                                  /* g_object_unref( ) */
-#include <librsvg-2/librsvg/rsvg.h>
+#include <librsvg/rsvg.h>
 
 typedef struct svg_rendition_t svg_rendition_t;