Don't redirect if user is already on port 80

[davidcx]

If user is already using port 80 but $original['port'] is set to 80 anyway, do not send a needless redirect.

wp-includes/canonical.php line 324

change from

if ( !empty( $original['port'] ) )

change to

if ( !empty( $original['port'] ) && $original['port'] != 80 )

Fixes, for example, Nagios's check_http getting sent a redirect rather than the page content.

-davidc

refreshed