Merge pull request #1421 from stianst/master

KEYCLOAK-1507

integration/tomcat/tomcat-core/src/main/java/org/keycloak/adapters/tomcat/AbstractKeycloakAuthenticatorValve.java

@@ -127,7 +127,9 @@ public abstract class AbstractKeycloakAuthenticatorValve extends FormAuthenticat
     }
 
     protected void beforeStop() {
-        nodesRegistrationManagement.stop();
+        if (nodesRegistrationManagement != null) {
+            nodesRegistrationManagement.stop();
+        }
     }
 
     private static InputStream getJSONFromServletContext(ServletContext servletContext) {