InviteMenu: Create menuitem before checking for Transports group

Otherwise modifying this menuitem later will fail (UnboundLocalError)
3 jobs for send-message-groups in 2 minutes and 54 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #16514
run-appdata

00:00:05

passed #16513
run-tests

00:02:37

 
  Build
passed #16515
run-build

00:00:12