keepalive: pass the correct arguments to HTTPResponse

python2.7's httplib.HTTPResponse takes the arguments in the following order:
    sock, debuglevel, strict, method, buffering

This was previously passing them in as positional and skipped strict, so we set
strict=method.  I'm explicitly setting strict=True now to preserve the previous
behavior that has been there since this file was created.

mercurial/keepalive.py

@@ -353,7 +353,8 b' class HTTPResponse(httplib.HTTPResponse)'
 
 
     def __init__(self, sock, debuglevel=0, strict=0, method=None):
-        httplib.HTTPResponse.__init__(self, sock, debuglevel, method)
+        httplib.HTTPResponse.__init__(self, sock, debuglevel=debuglevel,
+                                      strict=True, method=method)
         self.fileno = sock.fileno
         self.code = None
         self._rbuf = ''