dwatch(1): Eliminate ANSI dimming in developer mode

"Developer mode" (passing of "-dev" options), which enables debugging
features on compilation error, used to dim lines unrelated to error.

That proved distracting and feedback from testers also confirmed that
simply highlighting the line the compiler complains about is enough.

Sponsored by:	Smule, Inc.

cddl/usr.sbin/dwatch/dwatch

@@ -1057,10 +1057,6 @@ PSARGS_ACTION=$( cat <&9 )
 					slen = length(sprintf("%u", start))
 					elen = length(sprintf("%u", end))
 					N = elen > slen ? elen : slen
-					for (i = start; i <= end; i++) {
-						ti[i] = "\033[2m"
-						te[i] = "\033[22m"
-					}
 					ti[line] = "\033[31m"
 					te[line] = "\033[39m"
 					fmt = "%s%*u %s%s\n"