chore: fix typos

Applied fixes suggested by scripts/codespell.sh

src/events/payload.rs

@@ -59,7 +59,7 @@ pub enum EventType {
     /// or for functions that are expected to fail (eg. dc_continue_key_transfer())
     /// it might be better to delay showing these events until the function has really
     /// failed (returned false). It should be sufficient to report only the *last* error
-    /// in a messasge box then.
+    /// in a message box then.
     Error(String),
 
     /// An action cannot be performed because the user is not in the group.