clarified comments

Author: dmalan

src/sql.py

@@ -39,7 +39,7 @@ def execute(self, text, *multiparams, **params):
             elif result.lastrowid is not None:
                 return result.lastrowid
 
-            # if DELETE or UPDATE, return number of rows matched
+            # if DELETE or UPDATE (or INSERT without RETURNING), return number of rows matched
             else:
                 return result.rowcount