correct expected api version

src/environments/environment.dev.ts

@@ -6,6 +6,6 @@ export const environment = {
   production: false,
   testcenterUrl: '/api/',
   appPublisher: 'IQB - Institut zur Qualitätsentwicklung im Bildungswesen',
-  apiVersionExpected: '5.0.1',
+  apiVersionExpected: '6.0.0',
   veronaApiVersionSupported: '2.1.0'
 };

src/environments/environment.prod.ts

@@ -4,6 +4,6 @@ export const environment = {
   production: true,
   testcenterUrl: '/api/',
   appPublisher: 'IQB - Institut zur Qualitätsentwicklung im Bildungswesen',
-  apiVersionExpected: '5.0.1',
+  apiVersionExpected: '6.0.0',
   veronaApiVersionSupported: '2.1.0'
 };