Merge branch '2.1.x'

# Conflicts:
#	spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/actuate/GatewayControllerEndpointTests.java

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

@@ -847,7 +847,7 @@ spring:
         predicates:
         - Path=/foo/**
         filters:
-        - RewritePath=/foo/(?<segment>.*), /$\{segment}
+        - RewritePath=/foo(?<segment>/?.*), $\{segment}
 ----
 
 For a request path of `/foo/bar`, this will set the path to `/bar` before making the downstream request. Notice the `$` Should be replaced with `$\` because of the YAML spec.