Add patch for requests_tollbelt filename issue

Until requests/toolbelt#316 is merged, this will allow requests_toolbelt to send all the data needed by Proxmox

proxmoxer/backends/https.py

@@ -187,7 +187,8 @@ def request(self, method, url, params=None, data=None, headers=None, cookies=Non
         for k, v in data.copy().items():
             if is_file(v):
                 if getFileSize(v) > 2147483647:
-                    largeFiles[k] = v
+                    # add in filename from file pointer (patch for https://github.com/requests/toolbelt/pull/316)
+                    largeFiles[k] = (requests.utils.guess_filename(v), v)
                 else:
                     files[k] = v
                 del data[k]