Transport Key-Value pairs should be space separated

pt-spec says that the options should be space-separated:

 2.1.0.1. Bridge torrc lines

    Bridge lines specify how Tor should connect to a bridge. The Bridge
    line format is:
 
       Bridge [<transport>] <address>:<port> [<id-fingerprint>] [<k>=<v>] [<k>=<v>] [<k>=<v>]
 
    The PT-specific parts of this format are the [transport] and [k=v]
    values.
 
    <transport> is the name of the PT that MUST be used when connecting to
    the bridge, and the <k>=<v> values are PT-specific parameters that
    MUST be passed to the PT when connecting to the bridge (this MAY
    include keys, passwords or other PT configuration options) as
    specified in [CLIENTPARAMS].

we comma-separate them:

        args = ",".join(["%s=%s" % (k, v) for k, v in self.argdict.items()])