Proper requests parameters for multipart/form-data posting

Signed-off-by: SystemsPurge <[email protected]>

villas/controller/components/simulator.py

@@ -126,7 +126,7 @@ def _upload(self, filename):
             params["headers"] = {"Authorization":f"Bearer {self.t_up_token}"}
             self.t_up_token = None
         with open(filename, 'rb') as f:
-            params["data"] = f
+            params["files"] = {'upload_file':f}
             r = requests.post(**params)
             r.raise_for_status()
             self.logger.info(f'Uploaded file {filename} to {url}')