KEYCLOAK-8554 checked if master realm exist instead of number of realms for new installation check

services/src/main/java/org/keycloak/services/managers/ApplianceBootstrap.java

@@ -43,7 +43,7 @@ public class ApplianceBootstrap {
     }
 
     public boolean isNewInstall() {
-        if (session.realms().getRealms().size() > 0) {
+        if (session.realms().getRealm(Config.getAdminRealm()) != null) {
             return false;
         } else {
             return true;