vadmin: Log -S-file open errors with logger
vadmin: Log -S-file open errors with logger

with fprintf it goes to /dev/null when we're in the background.

Fixes #46

KristianLyng/vagent2,KristianLyng/vagent2,KristianLyng/vagent2,KristianLyng/vagent2,KristianLyng/vagent2,KristianLyng/vagent2,KristianLyng/vagent2