enable body caching if fallbackUri is configured

Signed-off-by: qnnn <65326092+qnnn@users.noreply.github.com>

Author: qnnn

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/SpringCloudCircuitBreakerFilterFactory.java

@@ -89,7 +89,9 @@ public List<String> shortcutFieldOrder() {
 
 	@Override
 	public GatewayFilter apply(Config config) {
-		enableBodyCaching(config.getRouteId());
+		if (config.getFallbackUri() != null) {
+			enableBodyCaching(config.getRouteId());
+		}
 		ReactiveCircuitBreaker cb = reactiveCircuitBreakerFactory.create(config.getId());
 		Set<HttpStatus> statuses = config.getStatusCodes()
 			.stream()