Fixed supplier function test config to GET

See gh-3646

Author: spencergibb

spring-cloud-gateway-server-mvc/src/test/java/org/springframework/cloud/gateway/server/mvc/handler/FunctionHandlerTests.java

@@ -20,7 +20,6 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -68,7 +67,6 @@ public void testTemplatedFunctionWorks() {
 			.isEqualTo("HELLO");
 	}
 
-	@Disabled
 	@Test
 	public void testSupplierFunctionWorks() {
 		restClient.get()
@@ -105,7 +103,7 @@ public RouterFunction<ServerResponse> gatewayRouterFunctionsSimpleFunction() {
 					.POST("/templatedfunction/{fnName}", fn("{fnName}"))
 					.build())
 				.and(route("testsupplierfunction")
-					.POST("/supplierfunction", fn("hello"))
+					.GET("/supplierfunction", fn("hello"))
 					.build());
 			// @formatter:on
 		}