Clippy fix

Author: mdecimus

src/parsers/message.rs

@@ -267,13 +267,11 @@ impl MessageParser {
                 let is_inline = is_inline
                     && part_headers
                         .header_value(&HeaderName::ContentDisposition)
-                        .map_or(true, |d| {
-                            !d.as_content_type().is_some_and(|ct| ct.is_attachment())
-                        })
+                        .is_none_or(|d| !d.as_content_type().is_some_and(|ct| ct.is_attachment()))
                     && (state.parts == 1
                         || state.mime_type != MimeType::MultipartRelated
                             && (mime_type == MimeType::Inline
-                                || content_type.map_or(true, |c| !c.has_attribute("name"))));
+                                || content_type.is_none_or(|c| !c.has_attribute("name"))));
 
                 // if message consists of single text/plain part, classify as text regardless
                 // of encoding issues: see malformed/018.eml