Fix merge issue

Author: RoderickJDunn

sqeleton/databases/redshift.py

@@ -142,7 +142,10 @@ def query_table_schema(self, path: DbPath) -> Dict[str, tuple]:
         try:
             return super().query_table_schema(path)
         except RuntimeError:
-            return self.query_external_table_schema(path)
+            try:
+                return self.query_external_table_schema(path)	
+            except RuntimeError:	
+                return self.query_pg_get_cols() 
 
     def _normalize_table_path(self, path: DbPath) -> DbPath:
         if len(path) == 1: