[11x] Mail\Mailable -> Attempt to read property "address" on array

[egekibar]

https://flareapp.io/share/NPL1w2o7

[taylorotwell]

Possible to add a test for this? How do you recreate it? Please mark as ready for review when the requested changes have been made.

[egekibar]

$template = new \App\Mail\Mailer();
$template->cc('test@example.com') ❌ not working

$template = new \App\Mail\Mailer();
$template->cc(['test@example.com']) ✅ working