fix(deltachat_rpc_client): make sphinx documentation display method parameters

Author: link2xt

deltachat-rpc-client/src/deltachat_rpc_client/_utils.py

@@ -187,13 +187,9 @@ class futuremethod:  # noqa: N801
     """Decorator for async methods."""
 
     def __init__(self, func):
-        functools.update_wrapper(self, func)
         self._func = func
 
     def __get__(self, instance, owner=None):
-        if instance is None:
-            return self
-
         def future(*args):
             generator = self._func(instance, *args)
             res = next(generator)
@@ -206,6 +202,7 @@ def f():
 
             return f
 
+        @functools.wraps(self._func)
         def wrapper(*args):
             f = future(*args)
             return f()