Add check for empty attributes list as well as null, in DelegatingMethodSecurityMetadataSource

Author: tekul

core/src/main/java/org/springframework/security/access/method/DelegatingMethodSecurityMetadataSource.java

@@ -53,7 +53,7 @@ public Collection<ConfigAttribute> getAttributes(Method method, Class<?> targetC
             Collection<ConfigAttribute> attributes = null;
             for (MethodSecurityMetadataSource s : methodSecurityMetadataSources) {
                 attributes = s.getAttributes(method, targetClass);
-                if (attributes != null) {
+                if (attributes != null && !attributes.isEmpty()) {
                     break;
                 }
             }