Add kwargs to WsgiMiddleware __init__
Add kwargs to WsgiMiddleware __init__

Add kwargs to this __init__ method is a way
to avoid some extra keyword arguments in local_conf [1].

    @classmethod
    def factory(cls, global_conf, **local_conf):
        def filter_(app):
            return cls(app, **local_conf)
        return filter_

These extra keyword arguments
can cause this exception (in case of ceilometer):
    `__init__() got an unexpected keyword argument`

[1] https://git.openstack.org/cgit/openstack/osprofiler/tree/osprofiler/web.py#n91

Change-Id: I82e0db75ef9f84075289e360428c09ec68fb72d9

stackforge/osprofiler,openstack/osprofiler,stackforge/osprofiler,stackforge/osprofiler,openstack/osprofiler,openstack/osprofiler