Remove no longer relevant text in 1993/Makefile

I added a temporary workaround for a problem in compilation that no
longer is needed but the XXX comment was not removed by mistake.

1993/Makefile

@@ -62,10 +62,6 @@ YEAR= 1993
 ###################
 #
 
-# XXX the $(MAKE) $$i is a temporary workaround while we get the other Makefiles
-# in order. It should read:
-#
-#	(cd $$i && $(MAKE) $$i):
 all:
 	@echo '=-=-= ${YEAR} begin make $@ =-=-='
 	@echo