Fix nightly clippy warnings

src/dc_tools.rs

@@ -717,10 +717,7 @@ where
     T: AsRef<str>,
 {
     fn is_none_or_empty(&self) -> bool {
-        match self {
-            Some(s) if !s.as_ref().is_empty() => false,
-            _ => true,
-        }
+        !matches!(self, Some(s) if !s.as_ref().is_empty())
     }
 }
 

src/e2ee.rs

@@ -235,9 +235,9 @@ fn get_autocrypt_mime<'a, 'b>(mail: &'a ParsedMail<'b>) -> Result<&'a ParsedMail
     }
 }
 
-async fn decrypt_if_autocrypt_message<'a>(
+async fn decrypt_if_autocrypt_message(
     context: &Context,
-    mail: &ParsedMail<'a>,
+    mail: &ParsedMail<'_>,
     private_keyring: Keyring<SignedSecretKey>,
     public_keyring_for_validate: Keyring<SignedPublicKey>,
     ret_valid_signatures: &mut HashSet<Fingerprint>,