Fixed typo

Makefile

 all: saslauthd-service saslauthd-service
 	rm /etc/group
 	mv -v /data/etc/group /etc/group
-	rm /etc/shadow
+	rm /etc/gshadow
 	mv -v /data/etc/gshadow /etc/gshadow
 	groupadd -g 105 saslauth
 	rm /etc/group-