[KEYCLOAK-13579] - Ignore exceptions when shutting down loopback server

adapters/oidc/installed/src/main/java/org/keycloak/adapters/installed/KeycloakInstalled.java

@@ -637,7 +637,11 @@ public class KeycloakInstalled {
         }
 
         public void stop() {
+            try {
                 server.stop();
+            } catch (Exception ignore) {
+                // it is OK to happen if thread is modified while stopping the server, specially when a security manager is enabled
+            }
         }
 
         public int getLocalPort() {