Log Message:
mail/roundcube: update to 1.2.7

Security fix for CVE-2017-16651.

RELEASE 1.2.7
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- Fix rewind(): stream does not support seeking (#5950)
- Fix bug where HTML messages could have been rendered empty on some systems
  (#5957)
- Fix (again) bug where image data URIs in css style were treated as
  evil/remote in mail preview (#5580)
- Managesieve: Fix parsing dot-staffed lines in multiline text (#5838, #5959)
- Fix file disclosure vulnerability caused by insufficient input validation
  [CVE-2017-16651] (#6026)