Dear maintainer,

currently, the xymon "kern" check is unable to correctly grep for the
kernel version, using "grep -E" which fails at "+deb13" in the installed
trixie kernel (6.12.38+deb13-amd64).

This is easily fixed by a small alteration to the parameters, outlined
in the patch below.

Thank you for your consideration.

Best regards
Christoph Zechner