editors/emacs: Update to version 26.1

NEWS: https://www.gnu.org/software/emacs/news/NEWS.26.1

Port changes

• Incorporate latest canna patches submitted by TAKANO Yuji <takachan@running-dog.net>.
• Remove workarounds for Bug 227799.
  • Configure succeeds whether devel/liblockfile is installed or not.
• Customize COMMENT for canna and nox flavors (reported by tobik).
• Remove legacy lldb for gud patch.
  • The patch added very little over running lldb on the command line. Moreover, gud is deprecated. Hopefully a lldb-mi will arrive soon.

Reviewed by: ashish (maintainer)
Differential Revision: https://reviews.freebsd.org/D15044