Fix member access in header

src/app/header/header.component.ts

@@ -32,6 +32,10 @@ export class HeaderComponent implements OnInit {
   }
 
   idpCompare(a: IdP, b: IdP): boolean {
-    return a !== undefined &&  b !== undefined && a.id === b.id;
+    if (!!a && !!b) {
+      return a.id === b.id;
+    } else {
+      return false;
+    }
   }
 }