pkgdir will always be set

This partially reverts commit 0ac93488952f (testing/sssd: revert bad
revert from the last commit").

Removing quotes around $pkgdir is not improvement at all; it should
be always quoted, to be safe if $pkgdir contains spaces.

Removing contributrs without first checking git log is not good.

This partially reverts commit 67a63bbbb70c24358c6dde9240a8babf2500cd08.

Removing quotes around $pkgdir is not improvement at all; it should be
always quoted, to be safe if $pkgdir contains spaces.

${pkgdir:?} is completely unnecessary and doesn't make much sense -
pkgdir is always set by abuild script.

Adding yourself to the contributors just for very minor (and even wrong)
changes in APKBUILD is not good.

bump to trigger rebuild with new libs