bug #591 Fix "Missing loader" detection in Webpack 4.34.0+ (Lyrkan)

This PR was merged into the master branch.

Discussion
----------

Fix "Missing loader" detection in Webpack 4.34.0+

In `[email protected]` having a missing loader can trigger a "You may need an **additional** loader" error message instead of the one we are currently looking for ("You may need an **appropriate** loader"), which causes one of our CI jobs to fail.

This PR fixes it by detecting both versions.

Related commit: webpack/webpack@45582c5#diff-34f95d7b09e1170360b8660f36c8b96fR26

Commits
-------

a798ae9 Fix "Missing loader" detection in Webpack 4.34.0+

Author: weaverryan

lib/friendly-errors/transformers/missing-loader.js

@@ -16,7 +16,7 @@ function isMissingLoaderError(e) {
         return false;
     }
 
-    if (!e.message.includes('You may need an appropriate loader')) {
+    if (!/You may need an (appropriate|additional) loader/.test(e.message)) {
         return false;
     }