mod_proxy_{connect,wstunnel}: follow up to r1657636.

Since rv is not used as an apr_status_t in the loop (it's logging is done by
proxy_{connect,wstunnel}_transfer() when necessary/relevent), use a boolean
instead to avoid the ugly ORs between APR error codes.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1669130 13f79535-47bb-0310-9956-ffa450edef68