[monaco] Fix bad preference initialization

first register override identifier, because monaco will immediately
update already  opened documents and then initialize with
bad preferences.

Fixes #6449

Signed-off-by: Sven Efftinge <sven.efftinge@typefox.io>

packages/monaco/src/browser/monaco-frontend-application-contribution.ts

@@ -35,8 +35,9 @@ export class MonacoFrontendApplicationContribution implements FrontendApplicatio
         }
         const registerLanguage = monaco.languages.register.bind(monaco.languages);
         monaco.languages.register = language => {
-            registerLanguage(language);
+            // first register override identifier, because monaco will immediately update already opened documents and then initialize with bad preferences.
             this.preferenceSchema.registerOverrideIdentifier(language.id);
+            registerLanguage(language);
         };
     }