[libgda] Using correct error report for unimplemented interface

[Pavlo Solntsev <psolntsev src gnome org>]

commit 2c823276a34fbdd7e9d6eef038c0bc61f0c3b8a0
Author: Pavlo Solntsev <p sun fun gmail com>
Date:   Fri May 29 00:01:52 2020 -0500

    Using correct error report for unimplemented interface

 libgda/gda-db-index.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/libgda/gda-db-index.c b/libgda/gda-db-index.c
index fae27b2d3..3f6616358 100644
--- a/libgda/gda-db-index.c
+++ b/libgda/gda-db-index.c
@@ -443,5 +443,9 @@ gda_db_index_rename (GdaDdlModifiable *old_name,
                      gpointer new_name,
                      GError **error)
 {
-  return TRUE;
+  g_set_error (error, GDA_DDL_MODIFIABLE_ERROR,
+               GDA_DDL_MODIFIABLE_NOT_IMPLEMENTED,
+               _("Operation is not implemented for the used provider"));
+
+  return FALSE;
 }