Fix installworld when the host does not need to bootstrap nmtree.

Reported by:	lev, jmg

Makefile.inc1

@@ -673,7 +673,7 @@ _zoneinfo=	zic tzsetup
 
 ITOOLS=	[ awk cap_mkdb cat chflags chmod chown \
 	date echo egrep find grep id install ${_install-info} \
-	ln lockf make mkdir mtree mv pwd_mkdb rm sed sh sysctl \
+	ln lockf make mkdir mtree mv nmtree pwd_mkdb rm sed sh sysctl \
 	test true uname wc ${_zoneinfo}
 
 #