remove unused dep; cargo clippy

src/model/tripdetails.rs

@@ -196,7 +196,7 @@ WHERE day = ? AND planned_starting_time = ?
         .fetch_one(db)
         .await
         .unwrap(); //TODO: fixme
-        let amount_currently_registered = i64::from(amount_currently_registered.count);
+        let amount_currently_registered = amount_currently_registered.count;
 
         amount_currently_registered >= self.max_people
     }