simplify Analyze C/C++ event configuration

There is no other configuration that the one for Retrace Server event
which is redundant. The redundat options can be replaced with
import-event-options element which is supported since libreport 2.2.0.

See libreport commit 5f491a3de842bcaea6cec33beab5e4f60c3bb5fe

Signed-off-by: Jakub Filak <jfilak@redhat.com>