Fix screensharing in 1:1 calls

Interface got changed in the group call branch and the modals don't
have enough typing to catch it.

Fixes element-hq/element-web#23808

src/components/views/voip/LegacyCallView.tsx

@@ -297,7 +297,9 @@ export default class LegacyCallView extends React.Component<IProps, IState> {
                 const [source] = await finished;
                 if (!source) return;
 
-                isScreensharing = await this.props.call.setScreensharingEnabled(true, source);
+                isScreensharing = await this.props.call.setScreensharingEnabled(true, {
+                    desktopCapturerSourceId: source,
+                });
             } else {
                 isScreensharing = await this.props.call.setScreensharingEnabled(true);
             }