Security update for hylafax+ (critical)

This update for hylafax+ fixes the following issues:

Security issues fixed in 5.6.1:

• CVE-2018-17141: multiple vulnerabilities affecting fax page reception in
  JPEG format Specially crafted input may have allowed remote execution of
  arbitrary code (boo#1109084)

Additionally, this update also contains all upstream corrections and
bugfixes in the 5.6.1 version, including:

• fix RFC2047 encoding by notify
• add jobcontrol PageSize feature
• don’t wait forever after +FRH:3
• fix faxmail transition between a message and external types
• avoid pagehandling from introducing some unnecessary EOM signals
• improve proxy connection error handling and logging
• add initial ModemGroup limits feature
• pass the user’s uid onto the session log file for sent faxes
• improve job waits to minimize triggers
• add ProxyTaglineFormat and ProxyTSI features