chore: adjust php comment usage hint

Co-authored-by: Côme Chilliet <91878298+come-nc@users.noreply.github.com>
Signed-off-by: John Molakvoæ <skjnldsv@users.noreply.github.com>

lib/public/Contacts/IManager.php

@@ -35,7 +35,7 @@ interface IManager {
 	 *  Following function shows how to search for contacts for the name and the email address.
 	 *
 	 *		public static function getMatchingRecipient($term) {
-	 *			$cm = \OC::$server->get(\OCP\Contacts\IManager::class);
+	 *			$cm = \OCP\Server::get(\OCP\Contacts\IManager::class);
 	 *			// The API is not active -> nothing to do
 	 *			if (!$cm->isEnabled()) {
 	 *				return array();