Small fixes after some testing

src/service/config.rs

@@ -27,6 +27,8 @@ impl From<ConfigDNSRecord> for domain::checker::DNSRecord {
 #[derive(Deserialize, Serialize, Clone)]
 pub struct Config {
     pub passphrase: String,
+
+    #[serde(default)]
     pub dns_records: Vec<ConfigDNSRecord>,
 
     #[serde(default = "default_interface_domain")]

src/service/gemini.rs

@@ -199,7 +199,7 @@ async fn listen(
 
     let listener = tokio::net::TcpListener::bind(addr)
         .await
-        .or_unexpected_while("binding tcp socket")?;
+        .expect("failed to bind tcp socket");
 
     loop {
         let (conn, addr) = tokio::select! {