Also remove the check for canEncrypt() since we also use this list for signing.

Change-Id: Ife95960f7303bebf2f61f5d3f3a37b9bb3018a5a
Reviewed-on: https://gerrit.libreoffice.org/35799Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Siegmund Gorr <siegmund.gorr@cib.de>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>