news/inn: Update to 2.6.3 and fix rnews

Update to 2.6.3 and fix a sandbox violation with the default build options when building under i.e. poudriere by moving rnews permissions to the plist.

Changelog https://www.eyrie.org/~eagle/software/inn/docs-2.6/news.html#S2

PR: 224670
Approved by: krion (mentor)
Sponsored by: BBOX.io
Differential Revision: https://reviews.freebsd.org/D22254