Rename and clear bad code

src/dictionary.rs

@@ -65,7 +65,7 @@ pub enum DictionaryMessage {
 }
 
 impl NavigatedPage<DictionaryMessage> for DictionaryState {
-    fn navigate(&self, message: &DictionaryMessage) -> Option<Page> {
+    fn navigate(&mut self, message: &DictionaryMessage) -> Option<Page> {
         if let Back = message {
             return Some(Page::PreviousPage);
         }