Clippy code cleanup

src/data_provider/words.rs

@@ -50,16 +50,14 @@ pub fn add_words(words: &mut[WordData], connection: &mut Connection) {
 
     let start_index = last_index - (count as u32) + 1;
 
-    let mut index = 0;
-    for id in start_index..=last_index {
+    for (index, id) in (start_index..=last_index).enumerate() {
         words[index].id = id;
-        index += 1;
     }
 }
 
 pub fn update_word(word: &mut WordData, connection: &Connection) {
     if word.id == 0 {
-        add_word(word, &connection);
+        add_word(word, connection);
     } else {
         connection
             .execute(
@@ -155,7 +153,7 @@ pub fn add_group(group: &mut WordGroup, connection: &Connection) {
 
 pub fn update_group(group: &mut WordGroup, connection: &Connection) {
     if group.id == 0 {
-        add_group(group, &connection);
+        add_group(group, connection);
     } else {
         connection
             .execute(