fix bugs (#892)

1. traffic stats not work.
2. magisk zip malformat

easytier/src/common/mod.rs

@@ -109,6 +109,9 @@ pub fn get_machine_id() -> uuid::Uuid {
     ))]
     let gen_mid = machine_uid::get()
         .map(|x| {
+            if x.is_empty() {
+                return uuid::Uuid::new_v4();
+            }
             let mut b = [0u8; 16];
             crate::tunnel::generate_digest_from_str("", x.as_str(), &mut b);
             uuid::Uuid::from_bytes(b)