fix: remove schema from firebird

plugins/dbgate-plugin-firebird/src/backend/sql/tables.js

@@ -2,8 +2,7 @@ module.exports = `
 SELECT
     TRIM(RDB$RELATION_NAME) AS "pureName",
     RDB$DESCRIPTION AS "objectComment",
-    RDB$FORMAT AS "objectTypeField",
-    TRIM(RDB$OWNER_NAME) AS "schemaName"
+    RDB$FORMAT AS "objectTypeField"
 FROM RDB$RELATIONS
 WHERE RDB$SYSTEM_FLAG = 0 -- only user-defined tables
 ORDER BY "pureName";