gst: make sure to include gstconfig.h also in gst_private.h

For GST_EXPORT define and also things like GST_DISABLE_REGISTRY.
Hopefully fixes the following build failure on cerbero-cross-mingw32:
helpers/gst-plugin-scanner.c:50: undefined reference to `_imp___gst_disable_registry_cache'

diff --git a/gst/gst_private.h b/gst/gst_private.h
index 25bed74..9d174c7 100644 (file)
--- a/gst/gst_private.h
+++ b/gst/gst_private.h
@@ -38,6 +38,9 @@ extern const char             g_log_domain_gstreamer[];
 #include <stdlib.h>
 #include <string.h>
 
+/* Needed for GST_EXPORT */
+#include "gstconfig.h"
+
 /* Needed for GstRegistry * */
 #include "gstregistry.h"
 #include "gststructure.h"