fix(frontend): migrate type changes

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/components/application-loader/application-loader.tsx

@@ -42,6 +42,8 @@ export const ApplicationLoader: React.FC<PropsWithChildren> = ({ children }) =>
           For further information look into the browser console.
         </Fragment>
       )
+    } else {
+      return null
     }
   }, [error])
 

frontend/src/components/application-loader/loading-screen/loading-screen.tsx

@@ -11,7 +11,7 @@ import React from 'react'
 import { Alert } from 'react-bootstrap'
 
 export interface LoadingScreenProps {
-  errorMessage?: string | ReactElement
+  errorMessage?: string | ReactElement | null
 }
 
 /**