Do not send emails from every cron job

Send them only when glab cannot boot within 2 minutes.

continuous/cron.sh

@@ -8,7 +8,7 @@ cd $(dirname $0)
 
 # Wakeup glab
 sudo /usr/sbin/etherwake 00:0c:f1:77:ec:46
-while ! ssh sojka@glab true; do sleep 1; done
+chronic timeout 2m sh -c 'while ! ssh sojka@glab true; do sleep 1; done'
 sleep 30 # Wait a bit to finish all boot jobs etc.
 
 mkdir -p logs