fixed unhandled errors in React DevTools bridge

Summary:
Unhandled errors from this plugin where showing up in our monitoring, made sure the error is handled now. Lowered to warning as this is probably a transient / connection issue.

See https://www.internalfb.com/logview/details/flipper_javascript/e7180deffd12e5900be754026780edbe/?trace_key=6abbef91dc1324bab958ca420ca70356&selected-logview-tab=All+Traces

Reviewed By: lblasa

Differential Revision: D44729212

fbshipit-source-id: 4c83eeab13bd2eb5c6f8ec563a35092eaf15fe30

desktop/plugins/public/reactdevtools/index.tsx

@@ -219,7 +219,9 @@ export function devicePlugin(client: DevicePluginClient<Events, Methods>) {
           },
           send(event: any, payload: any) {
             const data = {event, payload};
-            client.sendToServerAddOn('message', data);
+            client.sendToServerAddOn('message', data).catch((e) => {
+              console.warn(`Failed to send message to React devtools`, e);
+            });
           },
         };