Ensure blurhash is treated as optional

Fixes element-hq/element-web#18702

Author: turt2live

src/components/views/messages/MImageBody.tsx

@@ -393,7 +393,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
 
         const classes = classNames({
             'mx_MImageBody_thumbnail': true,
-            'mx_MImageBody_thumbnail--blurhash': this.props.mxEvent.getContent().info[BLURHASH_FIELD],
+            'mx_MImageBody_thumbnail--blurhash': this.props.mxEvent.getContent().info?.[BLURHASH_FIELD],
         });
 
         // This has incredibly broken types.
@@ -446,7 +446,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
 
     // Overidden by MStickerBody
     protected getPlaceholder(width: number, height: number): JSX.Element {
-        const blurhash = this.props.mxEvent.getContent().info[BLURHASH_FIELD];
+        const blurhash = this.props.mxEvent.getContent().info?.[BLURHASH_FIELD];
 
         if (blurhash) {
             if (this.state.placeholder === 'no-image') {

src/components/views/messages/MStickerBody.tsx

@@ -43,7 +43,7 @@ export default class MStickerBody extends MImageBody {
     // Placeholder to show in place of the sticker image if
     // img onLoad hasn't fired yet.
     protected getPlaceholder(width: number, height: number): JSX.Element {
-        if (this.props.mxEvent.getContent().info[BLURHASH_FIELD]) return super.getPlaceholder(width, height);
+        if (this.props.mxEvent.getContent().info?.[BLURHASH_FIELD]) return super.getPlaceholder(width, height);
         return <img src={require("../../../../res/img/icons-show-stickers.svg")} width="75" height="75" />;
     }