[Bug] Error in `client.util.change_my_password`
**Describe the bug**
Reported by Stefan Wolfsheimer, thanks Stefan!

`client.util.change_my_password` yields error:


```
DEBUG:urllib3.connectionpool:http://localhost:5000 "POST /api/recover/change HTTP/1.1" 404 232
Traceback (most recent call last):
  File "set_root_password.py", line 44, in <module>
    client.util.change_my_password(ORIG_ROOT_PASSWORD, ROOT_PASSWORD)
  File "/opt/vantage6/lib/python3.8/site-packages/vantage6/client/__init__.py", line 684, in change_my_password
    result = self.parent.request(
  File "/opt/vantage6/lib/python3.8/site-packages/vantage6/client/__init__.py", line 212, in request
    return self.request(endpoint, json, method, params,
  File "/opt/vantage6/lib/python3.8/site-packages/vantage6/client/__init__.py", line 217, in request
    return response.json()
  File "/opt/vantage6/lib/python3.8/site-packages/requests/models.py", line 900, in json
    return complexjson.loads(self.text, **kwargs)
  File "/usr/lib/python3.8/json/__init__.py", line 357, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.8/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.8/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
```

**Expected behavior**
Change password without error

diff --git a/vantage6-client/vantage6/client/__init__.py b/vantage6-client/vantage6/client/__init__.py
index 46bd8e3e..c25d4a40 100644
--- a/vantage6-client/vantage6/client/__init__.py
+++ b/vantage6-client/vantage6/client/__init__.py
@@ -682,7 +682,7 @@ class UserClient(ClientBase):
                 Message from the server
             """
             result = self.parent.request(
-                'recover/change', method='post', json={
+                'password/change', method='patch', json={
                     'current_password': current_password,
                     'new_password': new_password
                 }
['vantage6-client/vantage6/client/__init__.py']