busybox: switch to sha256 for passwd

Right now sha256 is considered more secure than md5, use it to harden
against password decryption.

Signed-off-by: Paul Spooren <[email protected]>

package/utils/busybox/Config-defaults.in

@@ -1366,7 +1366,7 @@ config BUSYBOX_DEFAULT_CHPASSWD
 	default n
 config BUSYBOX_DEFAULT_FEATURE_DEFAULT_PASSWD_ALGO
 	string
-	default "md5"
+	default "sha256"
 config BUSYBOX_DEFAULT_CRYPTPW
 	bool
 	default n