message: allow width, height, alt, title attributes in img
  fixes vector-im/riot-web#4646
diff: @@ -145,7 +145,7 @@ const sanitizeHtmlParams = {
  font: ['color', 'data-mx-bg-color', 'data-mx-color', 'style'], // custom to matrix
  span: ['data-mx-bg-color', 'data-mx-color', 'style'], // custom to matrix
  a: ['href', 'name', 'target', 'rel'], // remote target: custom to matrix
  - img: ['src'],
  + img: ['src', 'width', 'height', 'alt', 'title'],
  ol: ['start'],
  code: ['class'], // We don't actually allow all classes, we filter them in transformTags
  },
  