Fix Proxy web server middleware order (#51386) (#51424)

The limiter middleware was being executed prior to the middleware
responsible updating the client IP from X-Forwarded-For headers.
This results in erroneously enforcing connection limits in NAT
environments.

lib/service/service.go

@@ -4609,9 +4609,9 @@ func (process *TeleportProcess) initProxyEndpoint(conn *Connector) error {
 			Server: &http.Server{
 				Handler: utils.ChainHTTPMiddlewares(
 					webHandler,
-					makeXForwardedForMiddleware(cfg),
 					limiter.MakeMiddleware(proxyLimiter),
 					httplib.MakeTracingMiddleware(teleport.ComponentProxy),
+					makeXForwardedForMiddleware(cfg),
 				),
 				// Note: read/write timeouts *should not* be set here because it
 				// will break some application access use-cases.