Log Message:
sxhkd: Update x11/sxhkd to 0.5.9

pkgsrc changes:
 - Use `c99' (to adjust per-upstream Makefile)

Changes:
(unfortunately upstream does not provide any changelog, this is based and the
commit message)
0.5.9
-----
 - Honor LDFLAGS
 - Discard non tail chain states when locked (fixes #105)

0.5.8
-----
 - Write to the status fifo when a chain begins/ends (fixes #44)

Approved by <youri>, thanks!