Escape "--" in notifications

src/lib.rs

@@ -6,6 +6,7 @@ fn send_notification(icon_path: &str, nick: &str, text: &str) -> PyResult<()> {
     Command::new("notify-send")
         .arg("-i")
         .arg(icon_path)
+        .arg("--")
         .arg(format!("{}:", nick))
         .arg(text)
         .spawn()?;