Fix for canonical.php

[anatolykulikov]

In extremely rare cases it is impossible to determine the path

<?php
74. $original = parse_url( $requested_url );

I propose a very simple solution - check if the path was parsed correctly and if the host parameter has:

<?php
74. $original = parse_url( $requested_url );
75. if ( false === $original || !isset($original['host'])) {
76.     return;
77. }

You can simply check for the presence of this key, but if it is not there for some reason, then it is better to simply complete this function.