Uncaught TypeError in subscribe CGI with multiple digest flags in post/query data

[Mark Sapiro]

If a malicious user, bot or whatever POSTs or GETs with query data to the subscribe CGI and the data contains multiple 'digest=' fragments, the resultant digest data seen by the subscribe CGI is a list rather than a string. The CGI calls int() on this which throws TypeError.

The int() call is already in a try: that catches ValueError. It needs to catch TypeError too.