slap/hateoas: drop unwanted parameters and old compatibility

slapos/slap/hateoas.py

@@ -139,14 +139,6 @@ class ConnectionHelper:
 
       # XXX TODO: handle host cert verify
 
-      # Old behavior was to pass empty parameters as "None" value.
-      # Behavior kept for compatibility with old slapproxies (< v1.3.3).
-      # Can be removed when old slapproxies are no longer in use.
-      if data:
-        for k, v in six.iteritems(data):
-          if v is None:
-            data[k] = 'None'
-
       req = method(url=url,
                    params=params,
                    cert=cert,
@@ -197,8 +189,7 @@ class ConnectionHelper:
                           path=path,
                           data=json.dumps(data),
                           headers={'Content-type': 'application/json'},
-                          expect_json_error=True,
-                          cert_key=cert_key)
+    )
     return json_loads_byteified(req.text)