Don't ignore kwargs for uri style connections

mongoengine/connection.py

@@ -45,12 +45,14 @@ def register_connection(alias, name, host='localhost', port=27017,
         if uri_dict.get('database') is None:
             raise ConnectionError("If using URI style connection include "\
                                   "database name in string")
-        node = uri_dict['nodelist'][0]
-        host = node[0]
-        port = node[1]
-        name = uri_dict.get('database')
-        username = uri_dict.get('username') or username
-        password = uri_dict.get('password') or password
+        _connection_settings[alias] = {
+            'host': host,
+            'name': uri_dict.get('database'),
+            'username': uri_dict.get('username'),
+            'password': uri_dict.get('password')
+        }
+        _connection_settings[alias].update(kwargs)
+        return
 
     _connection_settings[alias] = {
         'name': name,
@@ -62,7 +64,6 @@ def register_connection(alias, name, host='localhost', port=27017,
         'password': password,
         'read_preference': read_preference
     }
-
     _connection_settings[alias].update(kwargs)