Switch disallowedMethods test to use PATCH

Update the requestsWithDisallowedMethodsAreRejected test to use PATCH
rather than HEAD. The change is to allow support for Spring Framework
4.3 which will implicitly map HEAD requests to GET.

Pre-flight requests are also only for "non-simple" HTTP methods [1]
(i.e. anything but GET, HEAD, POST) so there is really no such a thing
as a pre-flight request for HEAD.

[1] https://www.w3.org/TR/cors/#resource-preflight-requests

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/mvc/MvcEndpointCorsIntegrationTests.java

@@ -127,7 +127,7 @@ public class MvcEndpointCorsIntegrationTests {
 				"endpoints.cors.allowed-origins:foo.example.com");
 		createMockMvc()
 				.perform(options("/health").header(HttpHeaders.ORIGIN, "foo.example.com")
-						.header(HttpHeaders.ACCESS_CONTROL_REQUEST_METHOD, "HEAD"))
+						.header(HttpHeaders.ACCESS_CONTROL_REQUEST_METHOD, "PATCH"))
 				.andExpect(status().isForbidden());
 	}