fix mistake: missing "predicates" in config yml (#116)

add missing "predicates" in config yml

docs/src/main/asciidoc/spring-cloud-gateway.adoc

@@ -482,6 +482,7 @@ spring:
       # =====================================
       - id: rewritepath_route
         uri: http://example.org
+        predicates:
         - Path=/foo/**
         filters:
         - RewritePath=/foo/(?<segment>.*), /$\{segment}