The package ships ten executables and only the daemon reports a
version, so the generic per-executable probe warns for the other nine:
syslog-ng: 9/10 executables are missing version 4.12.0
The tools next to the daemon print their usage instead, which the probe
cannot read a version from. Assert the version on syslog-ng itself.
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>