In parserange(), we tested wether range was null, to test wether or not the repeat number was the end of the string (to test if we had something like "*/3/34"). But it is str that we should be testing, not range, as its value as a pointer doesn't mean anything in the current context.
This makes this cron more in line with other interpretations concerning '~'. In other crons, a random number is picked for the starting field, and it doesn't change during all of the program's lifetime, whereas this one used to change its random number everytime it was matched.
