Update app.py

app.py

@@ -94,7 +94,7 @@ def main():
             elif src_from_file_:
                 src_ = src_from_file_
             tgt_ = tgt_from_file_
-            if not src_ or not tgt_:
+            if (not src_ and not src_text_) or not tgt_:
                 logging.warning("source or target are not provided")
                 return
             return service_request(src_text_, src_, tgt_, api_key_, api_secret_)