mhlsbr.c: Don't strchr(3) non-string NUL-less buffer.

[nmh] / etc / mhl.digest

width=80,overflowoffset=10
leftadjust,compress,compwidth=9
Date:formatfield="%<(nodate{text})%{text}%|%(tws{text})%>"
From:
Subject:
:
body:nocomponent,overflowoffset=0,noleftadjust,nocompress