Fix open in browser doesn't work in WSL

On Linux, `x-default-browser` requires `xdg-utils` to be installed to
determine a default browser. So it fails when it's not installed.
However, in WSL, we still can open a browser without it. Now it
fallbacks to `open` when `x-default-browser` fails which makes it work on WSL
without `xdg-utils`.

lib/core-server/src/utils/open-in-browser.ts

@@ -7,7 +7,7 @@ import dedent from 'ts-dedent';
 export function openInBrowser(address: string) {
   getDefaultBrowser(async (err: any, res: any) => {
     try {
-      if (res.isChrome || res.isChromium) {
+      if (res && (res.isChrome || res.isChromium)) {
         // We use betterOpn for Chrome because it is better at handling which chrome tab
         // or window the preview loads in.
         betterOpn(address);