Fix missing property in Create Sync Job request

In example there was property called "user1", but it was missing from request definition.

This resulted in nswagger generating incorrect C# API code.

data/web/api/openapi.yaml

@@ -1531,6 +1531,9 @@ paths:
                 port1:
                   description: the smtp port of the target mail server
                   type: string
+                user1:
+                  description: the username of the mailbox
+                  type: string
                 password:
                   description: the password of the mailbox
                   type: string