CDB_Federated_Table_Register: Handle conflict nicely

test/CDB_FederatedServerTables_expect

@@ -53,4 +53,12 @@ ERROR:  non geometry column "Does not exists"
 ## Registering a table: NULL webmercator_column is OK
 
 
+## Target conflict is handled nicely: Table
+CREATE TABLE
+ERROR:  Could not import table "remote_geom" as "localtable": "localtable" already exists
+## Target conflict is handled nicely: View
+CREATE VIEW
+ERROR:  Could not import table "remote_geom" as "localtable2": "localtable2" already exists
+DROP VIEW
+DROP TABLE
 D1|