configure: fix build with --disable-external
diff --git a/configure.ac b/configure.ac
index f99521b..3b4074d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -674,9 +674,6 @@
     AG_GST_GL_PLUGIN_CHECKS
   fi
 ])
-AM_CONDITIONAL(HAVE_GRAPHENE, test "x$HAVE_GRAPHENE" = "xyes")
-AM_CONDITIONAL(HAVE_PNG, test "x$HAVE_PNG" = "xyes")
-AM_CONDITIONAL(HAVE_JPEG, test "x$HAVE_JPEG" = "xyes")
 
 dnl *** ivorbis ***
 dnl AM_PATH_IVORBIS only takes two options
@@ -791,6 +788,10 @@
 
 fi dnl of EXT plugins
 
+AM_CONDITIONAL(HAVE_GRAPHENE, test "x$HAVE_GRAPHENE" = "xyes")
+AM_CONDITIONAL(HAVE_PNG, test "x$HAVE_PNG" = "xyes")
+AM_CONDITIONAL(HAVE_JPEG, test "x$HAVE_JPEG" = "xyes")
+
 dnl *** gio-unix-2.0 for tests/check/pipelines/tcp.c ***
 PKG_CHECK_MODULES(GIO_UNIX_2_0, gio-unix-2.0 >= 2.24,
     HAVE_GIO_UNIX_2_0="yes",