Bump buildroot to version 2017-02

TG-3 #closed

bsp/buildroot/system/skeleton/etc/group

@@ -22,5 +22,5 @@ plugdev:x:46:
 staff:x:50:
 lock:x:54:
 netdev:x:82:
-nogroup:x:99:
 users:x:100:
+nogroup:x:65534:

bsp/buildroot/system/skeleton/etc/passwd

@@ -6,4 +6,4 @@ sync:x:4:100:sync:/bin:/bin/sync
 mail:x:8:8:mail:/var/spool/mail:/bin/false
 www-data:x:33:33:www-data:/var/www:/bin/false
 operator:x:37:37:Operator:/var:/bin/false
-nobody:x:99:99:nobody:/home:/bin/false
+nobody:x:65534:65534:nobody:/home:/bin/false