feat: another variation

..that is often seen on Windows like this:
```
An unexpected error occurred: "https://registry.yarnpkg.com/@private/ngffwd-node-processes/-/ngffwd-node-processes-1.0.123.tgz: Request failed "404 Not Found".
```

re yarnpkg/yarn#2738

index.js

@@ -10,7 +10,7 @@ module.exports = function (command, args, options, callback) {
     process.env.npm_config_color = 0;
 
     var attempt = exec(runCmd, function (err, stdout, stderr) {
-      matchers = [/unexpected end of file/ig, /the registry may be down/ig];
+      matchers = [/unexpected end of file/ig, /the registry may be down/ig, /Request failed "404/ig];
       var match = matchers.some(function (matcher) {
           return stdout.match(matcher) || stderr.match(matcher);
       });

package.json

@@ -1,7 +1,7 @@
 {
   "name": "yarn-retry",
   "description": "retry yarn when it fails",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "repository": {
     "url": "git://github.com/artemv/yarn-retry.git"
   },

test/main.tests.js

@@ -27,4 +27,5 @@ describe('npm-install-retry', function () {
   }
 
   testRetries('echo An unexpected error occurred: "https://registry.yarnpkg.com/@private/ngffwd-node-processes/-/ngffwd-node-processes-1.0.123.tgz: unexpected end of file".');
+  testRetries('echo An unexpected error occurred: "https://registry.yarnpkg.com/@private/ngffwd-node-processes/-/ngffwd-node-processes-1.0.123.tgz: Request failed \\"404 Not Found\\"".');
 });