Added the following to roundup/cgi/client.py-Client::main()

        # strip HTTP_PROXY issue2550925 in case                                 
        # PROXY header is set.                                                  
        if 'HTTP_PROXY' in self.env:
            del(self.env['HTTP_PROXY'])
        if 'HTTP_PROXY' in os.environ:
            del(os.environ['HTTP_PROXY'])

This removes the variable from code flows in the rest, xmlrpc and
inner_main (web) interface.

Any review notes Ralf?