kiss-maintainer: fix CRUX-style usage

[aabacchus]

Commit d94c811 changed sort -u to uniq -u; these are not equivalent. uniq -u suppresses all duplicate lines, but sort -u removes all but one. In the case of there being no command-line args, PWD is taken as the package, and if that package is in a repo already in KISS_PATH, the repo will be in KISS_PATH twice. This will cause the kiss search command to give two entries for PWD, and uniq -u removes both. Revert to sort -u to keep one of those entries.

If the package in PWD is not installed, there will be not entries left; if it is installed, kiss-maintainer will try to get the history from /var/db/kiss/installed/pkg, which is not a git repo.

Example of the incorrect behaviour:

KISS_PATH=/home/me/repo/core
PWD=/home/me/repo/core/musl
$ sh -x /usr/bin/kiss-maintainer
+ '['  ]
+ export 'KISS_PATH=/home/me/repo/core::/home/me/repo/core'
+ set -- musl
+ kiss search musl
+ uniq -u
+ read -r repo
+ read -r repo
+ cd /var/db/kiss/installed/musl
+ git log -1 version
+ m=
+ :
+ m=
+ m=
+ '['  ]
+ continue
+ read -r repo

(no output)

[aabacchus]

Ah, I see it was PR #183.