[Fedora-suds-list] Patch to message sending plugin function.

[Sean True]

The last two lines of this patch allow the plugin to actually modify
the outbound message. It is bit crass to allow this, but it was useful
-- and the docs led me to
believe it should be possible. Other plugins probably have objects
which can support in-place modification, but the envelope here is a
string.

            soapenv = soapenv.encode('utf-8')
            ctx = plugins.message.sending(envelope=soapenv)
            soapenv = ctx.envelope