fix(i18n): remove duplicated traduction

Author: Akinator31

src/i18n/language/en.rs

@@ -633,10 +633,6 @@ pub fn load_english_messages(dict: &mut ErrorDictionary) {
         "slash_command.new_thread_user_id_argument".to_string(),
         DictionaryMessage::new("The ID of the user to create the thread for"),
     );
-    dict.messages.insert(
-        "slash_command.new_thread_user_id_argument".to_string(),
-        DictionaryMessage::new("The ID of the user to create the thread for"),
-    );
     dict.messages.insert(
         "slash_command.close_command_description".to_string(),
         DictionaryMessage::new("Close the current thread"),