No error from unquoted numbers in ReplaceIfNoLinesMatching

[Chip Seraphine]

Just spent a lot of time debugging a problem with editfiles not updating a 
file, and it turned out the reason was that I had:

ReplaceLinesMatchingField 6

instead of

ReplaceLinesMatchingField "6"

The annoying thing was that even at -d2 I was not getting an error message for 
this; the line was just being ignored.  Grr.  We really ought to get at least 
a warning for this, since it results in Surprising Behavior.

Maybe it is just the friday afternoon brainfog, but I didn't see where the 
error message ought to go for this one, or I'd send a patch.