thunderbird-kde: fix build

5 jobs for master in 46 minutes and 51 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Package
passed #9061
PKGBUILD
build_pkgs

00:43:39

failed #9047
PKGBUILD
build_pkgs

00:02:09

 
  Sign
passed #9048
signature
sign_pkgs

00:01:49

 
  Deploy
passed #9049
rsync manual
deploy_pkgs

00:00:38

 
  Stable
passed #9050
rsync manual
move_pkgs_to_stable

00:00:43