Not sanitized input variable and non-strict comparison

[rickhurst]

These are instances of a Non-sanitized input variable and a non-strict comparison which have been flagged in recent VIP Code Reviews and could do with addressing or silencing as applicable:-

Co-Authors-Plus/php/class-coauthors-wp-list-table.php

Line 80 in 3a4cc36

$args['meta_key'] = $coauthors_plus->guest_authors->get_post_meta_key( $_REQUEST['orderby'] );

Co-Authors-Plus/upgrade.php

Line 42 in 3a4cc36

if ( is_object( $legacy_coauthor_login ) && ! in_array( $legacy_coauthor_login->user_login, $coauthors ) ) {