Custom ports cause getaddrinfo-related exceptions with chunked uploads

[briancline]

ChunkedUploadConnection doesn't seem to be ensuring that any port it parses out of the connection string is actually an int() before passing it onto an HTTPConnection/HTTPSConnection object. From there, it is expected to be an int, and getaddrinfo will also want this.

Currently this barfs with an extremely misleading "Disconnected" exception with a 0 status code.