Sending a Message causes crash in GUI

[Geo25rey]

Problem

When sending a message from the message composer GUI, the program crashes with the following stacktrace.

  goroutine 51106 [running]:
   ipmail/libipmail/crypto.(identityList).GetAny(0xc00012df70, 0xc000b92750)
       /Users/runner/work/ipmail/ipmail/libipmail/crypto/identity_list.go:64 +0x2e
   ipmail/gui/fyne_views.MakeMessageComposer.func1()
       /Users/runner/work/ipmail/ipmail/gui/fyne_views/message_composer.go:42 +0x292
   fyne.io/fyne/widget.(Button).Tapped(0xc001cc8210, 0xc005fd1660)
       /Users/runner/go/pkg/mod/fyne.io/fyne@v1.4.1/widget/button.go:192 +0xa7
   fyne.io/fyne/internal/driver/glfw.(window).mouseClicked.func5()
       /Users/runner/go/pkg/mod/fyne.io/fyne@v1.4.1/internal/driver/glfw/window.go:734 +0x38
   fyne.io/fyne/internal/driver/glfw.(window).runEventQueue(0xc0044056c0)
       /Users/runner/go/pkg/mod/fyne.io/fyne@v1.4.1/internal/driver/glfw/window.go:1152 +0x7a
   created by fyne.io/fyne/internal/driver/glfw.(*gLDriver).createWindow.func1
       /Users/runner/go/pkg/mod/fyne.io/fyne@v1.4.1/internal/driver/glfw/window.go:1176 +0x10d