Use random hour for cron job

The hour for the cron job isn't really random (as is the minute),
but assuming acme.sh installation times are not correlated, neither
will be the resulting cron start times.

acme.sh

@@ -5590,6 +5590,7 @@ installcronjob() {
   fi
   _t=$(_time)
   random_minute=$(_math $_t % 60)
+  random_hour=$(_math $_t / 60 % 24)
 
   if ! _exists "$_CRONTAB" && _exists "fcrontab"; then
     _CRONTAB="fcrontab"
@@ -5616,12 +5617,12 @@ installcronjob() {
     if _exists uname && uname -a | grep SunOS >/dev/null; then
       $_CRONTAB -l | {
         cat
-        echo "$random_minute 0 * * * $lesh --cron --home \"$LE_WORKING_DIR\" $_c_entry> /dev/null"
+        echo "$random_minute $random_hour * * * $lesh --cron --home \"$LE_WORKING_DIR\" $_c_entry> /dev/null"
       } | $_CRONTAB --
     else
       $_CRONTAB -l | {
         cat
-        echo "$random_minute 0 * * * $lesh --cron --home \"$LE_WORKING_DIR\" $_c_entry> /dev/null"
+        echo "$random_minute $random_hour * * * $lesh --cron --home \"$LE_WORKING_DIR\" $_c_entry> /dev/null"
       } | $_CRONTAB -
     fi
   fi