Typo fixes in 1992/nathan

In nathan.c there was also a typo fix but since it's not the original
entry (or any thing like it) it's okay to do this. This is actually the
subject of a discussion to be had on GitHub which I'll be addressing in
a bit.

In README.md there was also a typo fixed.

1992/nathan/README.md

@@ -43,7 +43,7 @@
 	diff nathan.c barfoof.c
 
     WARNING:
-	The judges' make no claim as to the strength or security
+	The judges make no claim as to the strength or security
 	of this program.  It is likely to be nil, or the next
 	best thing to it.  Still, you might consider installing
 	it in /usr/games/nathan.  :-)