style: fix rustfmt formatting in challenge.rs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: adrgs

src/src/certs/challenge.rs

@@ -26,20 +26,14 @@ impl HttpChallengeHandler {
 
     /// Store a challenge token and its key authorization
     pub fn set_token(&self, token: &str, key_authorization: &str) {
-        let mut tokens = self
-            .tokens
-            .write()
-            .expect("challenge token lock poisoned");
+        let mut tokens = self.tokens.write().expect("challenge token lock poisoned");
         tokens.insert(token.to_string(), key_authorization.to_string());
         info!("Set HTTP-01 challenge token: {}", token);
     }
 
     /// Remove a challenge token after validation
     pub fn clear_token(&self, token: &str) {
-        let mut tokens = self
-            .tokens
-            .write()
-            .expect("challenge token lock poisoned");
+        let mut tokens = self.tokens.write().expect("challenge token lock poisoned");
         tokens.remove(token);
         info!("Cleared HTTP-01 challenge token: {}", token);
     }