make globals more simple

src/backend/mod.rs

@@ -212,21 +212,13 @@ impl Backend {
   }
 }
 
+#[derive(Default)]
 /// HashMap and some meta information for multiple Backend structs.
 pub struct Backends {
   pub apps: HashMap<ServerNameBytesExp, Backend>, // hyper::uriで抜いたhostで引っ掛ける
   pub default_server_name_bytes: Option<ServerNameBytesExp>, // for plaintext http
 }
 
-impl Default for Backends {
-  fn default() -> Self {
-    Self {
-      default_server_name_bytes: None,
-      apps: HashMap::<ServerNameBytesExp, Backend>::default(),
-    }
-  }
-}
-
 pub type SniServerCryptoMap = HashMap<ServerNameBytesExp, Arc<ServerConfig>>;
 pub struct ServerCrypto {
   // For Quic/HTTP3, only servers with no client authentication