Remove stale PHPMailer baseline entry from PHPStan

The PHPMailer $Port type error no longer occurs since registers.php
now uses the SMTP adapter instead of PHPMailer directly.

phpstan-baseline.neon

@@ -138,12 +138,6 @@ parameters:
 			count: 1
 			path: app/init/registers.php
 
-		-
-			message: '#^Property PHPMailer\\PHPMailer\\PHPMailer\:\:\$Port \(int\) does not accept string\.$#'
-			identifier: assign.propertyType
-			count: 1
-			path: app/init/registers.php
-
 		-
 			message: '#^Variable \$providerConfig in empty\(\) always exists and is not falsy\.$#'
 			identifier: empty.variable