verify_peer in dsn should be 0

Setting it to false value resolves to true in php 7.4 since false is taken as string.

Author: fliespl

components/mailer.rst

@@ -171,7 +171,7 @@ configurable with the ``verify_peer`` option. Although it's not recommended to
 disable this verification for security reasons, it can be useful while developing
 the application or when using a self-signed certificate::
 
-    $dsn = 'smtp://user:pass@smtp.example.com?verify_peer=false'
+    $dsn = 'smtp://user:pass@smtp.example.com?verify_peer=0'
 
 .. versionadded:: 5.1