fix breakage found by mass one-applet builds

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/update_passwd.c b/libbb/update_passwd.c
index 6255af4..95423d1 100644
--- a/libbb/update_passwd.c
+++ b/libbb/update_passwd.c
@@ -180,6 +180,7 @@
 		if (!line) /* EOF/error */
 			break;
 
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
 		if (!name && member) {
 			/* Delete member from all groups */
 			/* line is "GROUP:PASSWD:[member1[,member2]...]" */
@@ -209,6 +210,7 @@
 			fprintf(new_fp, "%s\n", line);
 			goto next;
 		}
+#endif
 
 		cp = is_prefixed_with(line, name_colon);
 		if (!cp) {