optimize code

src/css.rs

@@ -88,8 +88,8 @@ pub fn process_css<'a>(
 ) -> Result<String, ParseError<'a, String>> {
     let mut result: String = "".to_string();
 
-    let mut curr_rule: String = rule_name.clone().to_string();
-    let mut curr_prop: String = prop_name.clone().to_string();
+    let mut curr_rule: String = rule_name.to_string();
+    let mut curr_prop: String = prop_name.to_string();
     let mut token: &Token;
     let mut token_offset: SourcePosition;
 

src/html.rs

@@ -601,7 +601,7 @@ pub fn retrieve_and_embed_asset(
     options: &Options,
     depth: u32,
 ) {
-    let resolved_url: Url = resolve_url(document_url, attr_value.clone());
+    let resolved_url: Url = resolve_url(document_url, attr_value);
 
     match retrieve_asset(
         cache,