Fix crash when changing composer From address

Fixes #538
4 jobs for wip/538-crash-changing-from in 19 minutes and 37 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #395249
ubuntu

00:08:32

 
  Test
passed #395250
flatpak

00:09:58

 
  Deploy
passed #395251
review

00:00:35

passed #395252
allowed to fail manual
stop_review

00:00:31