Fix component exesql bug (#2042)

### What problem does this PR solve?

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

api/apps/canvas_app.py

@@ -175,6 +175,6 @@ def test_db_connect():
                                     password=req["password"])
         db.connect()
         db.close()
-        return get_json_result(retmsg="Database Connection Successful!")
+        return get_json_result(data="Database Connection Successful!")
     except Exception as e:
         return server_error_response(e)