Fix for another API change

Author: Dave Syer

spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/RestConfiguration.java

@@ -42,6 +42,7 @@
 import static org.springframework.http.codec.BodyInserters.fromPublisher;
 
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 import reactor.ipc.netty.NettyContext;
 import reactor.ipc.netty.http.server.HttpServer;
 
@@ -72,7 +73,7 @@ public HttpHandler httpHandler(FunctionRegistry registry) {
 				: registry.composeFunction(
 						StringUtils.commaDelimitedListToStringArray(name));
 		FunctionInvokingHandler handler = new FunctionInvokingHandler(function);
-		RouterFunction<Publisher<String>> route = RouterFunctions.route(
+		RouterFunction<ServerResponse> route = RouterFunctions.route(
 				RequestPredicates.POST(webProperties.getPath())
 						.and(RequestPredicates.contentType(MediaType.TEXT_PLAIN)),
 				handler::handleText);
@@ -92,7 +93,7 @@ private FunctionInvokingHandler(Function<Flux<String>, Flux<String>> function) {
 			this.function = function;
 		}
 
-		private ServerResponse<Publisher<String>> handleText(ServerRequest request) {
+		private Mono<ServerResponse> handleText(ServerRequest request) {
 			Flux<String> input = request.body(toFlux(String.class));
 			Publisher<String> output = this.function.apply(input);
 			return ServerResponse.ok().body(fromPublisher(output, String.class));