textproc/sigil: update to 0.9.12
jonc@chen.org.nz steps up to maintain the port
ChangeLog: https://github.com/Sigil-Ebook/Sigil/releases/tag/0.9.12
- fix typo in cssreformatter that caused errors with @ fontface (issue #394)
- workaround for qt bug affecting tab close buttons on Mac (commit f3b9399)
- fix Mac Qt5 plugin dylibs that macdeployqt broke in Sigil-0.9.11
PR: 235873
Submitted by: jonc@chen.org.nz (maintainer)