Security update for znc (moderate)

This update for znc fixes the following issues:

• Update to version 1.7.1
  • CVE-2018-14055: non-admin user could gain admin privileges and shell
    access by injecting values into znc.conf (bnc#1101281)
  • CVE-2018-14056: path traversal in HTTP handler via …/ in a web skin
    name. (bnc#1101280)
• Update to version 1.7.0
  • Make ZNC UI translateable to different languages
  • Configs written before ZNC 0.206 can’t be read anymore
  • Implement IRCv3.2 capabilities away-notify, account-notify,
    extended-join
  • Implement IRCv3.2 capabilities echo-message, cap-notify on the "client
    side"
  • Update capability names as they are named in IRCv3.2:
    znc.in/server-time-iso→server-time, znc.in/batch→batch. Old names
    will continue working for a while, then will be removed in some future
    version.
  • Make ZNC request server-time from server when available
  • Add "AuthOnlyViaModule" global/user setting
  • Stop defaulting real name to "Got ZNC?"
  • Add SNI SSL client support
  • Add support for CIDR notation in allowed hosts list and in trusted
    proxy list
  • Add network-specific config for cert validation in addition to
    user-supplied fingerprints: TrustAllCerts, defaults to false, and
    TrustPKI, defaults to true.
  • Add /attach command for symmetry with /detach. Unlike /join it allows
    wildcards.
• Update to version 1.6.6:
  • Fix use-after-free in znc --makepem. It was broken for a long time,
    but started segfaulting only now. This is a useability fix, not a
    security fix, because self-signed (or signed by a CA) certificates can
    be created without using --makepem, and then combined into znc.pem.