message: fix(omemo): ignore case for encrypted image
diff: @@ -179,7 +179,7 @@ export default class OMEMOPlugin extends EncryptionPlugin {
  lines[0] = undefined;
  let [match, , filename, extension] = matches;
  - let mime = /^(jpeg|jpg|gif|png|svg)$/.test(extension) ? `image/${extension}` : 'application/octet-stream';
  + let mime = /^(jpeg|jpg|gif|png|svg)$/i.test(extension) ? `image/${extension.toLowerCase()}` : 'application/octet-stream';
  let attachment = new Attachment(filename, mime, match);
  attachment.setData(match);
  