fixed failregex line for roundcube 0.9+

# Only works only if  log driver: is set to  'syslog'. this is becoz fail2ban fails to 'read' the line due to the
 brackets around the date timestamp on logline when log driver is set to file
failregex when roundcube log driver is set to 'syslog'
Merge branch 'patch-3' extending roundcube failregex to support v0.9+ (from https://github.com/teroz/fail2ban)

* 'patch-3' of https://github.com/teroz/fail2ban:
  failregex when roundcube log driver is set to 'syslog'
  fixed failregex line for roundcube 0.9+
DOC: Changelog entry fro preceeding merge from Terence