…unnel usage)

GCS server does not handle requests with port, and simply report an
error:

    <?xml version="1.0"?>
    <?xml version='1.0' encoding='UTF-8'?>
    <Error>
        <Code>InvalidURI</Code>
        <Message>Couldn't parse the specified URI.</Message>
        <Details>Invalid URL: storage.googleapis.com:443/...</Details>
    </Error>

Removing the port fixes the issue. Note that there is port in the Host
header anyway.

Note, this is a problem only for proxy in a tunnel mode, since only it
sends such requests, other sends requests directly via HTTP methods.