[eog] EogMetadataReader: Make interface internal again

[Felix Riemann <friemann src gnome org>]

commit a7737bd3d9fc6e602e93c40798cb7c82ea2a0b95
Author: Felix Riemann <friemann gnome org>
Date:   Sat Jul 9 20:14:21 2022 +0200

    EogMetadataReader: Make interface internal again
    
    In b3f7059e the `G_GNUC_INTERNAL` token got lost which made the
    `_get_type()` function externally visible on the library.
    Re-add the token to make the interface fully private again.

 src/eog-metadata-reader.h | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/eog-metadata-reader.h b/src/eog-metadata-reader.h
index 3b82f544..f1cd9e4a 100644
--- a/src/eog-metadata-reader.h
+++ b/src/eog-metadata-reader.h
@@ -36,6 +36,7 @@
 G_BEGIN_DECLS
 
 #define EOG_TYPE_METADATA_READER             (eog_metadata_reader_get_type ())
+G_GNUC_INTERNAL
 G_DECLARE_INTERFACE (EogMetadataReader, eog_metadata_reader, EOG, METADATA_READER, GObject);
 
 struct _EogMetadataReaderInterface {