Add -O0 instead of -O2 to CFLAGS with build_nmh -d option.

[nmh] / etc / rcvdistcomps

%(void(localmbox))%(void(width))%(putaddr Resent-From: )
%(lit)%(formataddr{addresses})\
%<(nonnull)%(void(width))%(putaddr Resent-To: )\n%>