match on single host/port only for integer port

match on single host/port only for integer port

Fixed regression caused by improvements to PostgreSQL URL parsing in
:ticket:`10004` where "host" query string arguments that had colons in
them, to support various third party proxy servers and/or dialects, would
not parse correctly as these were evaluted as ``host:port`` combinations.
Parsing has been updated to consider a colon as indicating a ``host:port``
value only if the hostname contains only alphanumeric characters with dots
or dashes only (e.g. no slashes), followed by exactly one colon followed by
an all-integer token of zero or more integers.  In all other cases, the
full string is taken as a host.

Fixes: #10069
Change-Id: I77beb27e44abc0a66aa0810de855daa4186dacfd