Merge lp://qastaging/~cypressyew/checkbox/fix-autostart-vivid into lp://qastaging/checkbox

Rewrite the if statement from "&&" style to the normal if statement, in this way it won't return error value when the package does not exist.

Let's expand it:
sh -c "
if [ `pidof systemd` ]; then
    sudo systemctl start checkbox-ci-installed-notifier.service;
    /usr/bin/checkbox sru --check-config >/tmp/checkbox.log 2>&1;
    sudo systemctl start checkbox-ci-mailer.service;
else
    sudo initctl emit checkbox-sru-started;
    /usr/bin/checkbox sru --check-config >/tmp/checkbox.log 2>&1;
    sudo initctl emit checkbox-sru-finished;
fi"