internal: fix incorrect metric calculation (#19701)

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

internal/web/proxy.go

@@ -75,6 +75,7 @@ func (ws *WebServer) configureProxy() {
 			return
 		}
 		before := time.Now()
+
 		if ws.ProxyServer != nil && ws.ProxyServer.HandleHost(rw, r) {
 			elapsed := time.Since(before)
 			Requests.With(prometheus.Labels{
@@ -82,12 +83,14 @@ func (ws *WebServer) configureProxy() {
 			}).Observe(float64(elapsed) / float64(time.Second))
 			return
 		}
+
+		r.Body = http.MaxBytesReader(rw, r.Body, maxBodyBytes)
+		rp.ServeHTTP(rw, r)
+
 		elapsed := time.Since(before)
 		Requests.With(prometheus.Labels{
 			"dest": "core",
 		}).Observe(float64(elapsed) / float64(time.Second))
-		r.Body = http.MaxBytesReader(rw, r.Body, maxBodyBytes)
-		rp.ServeHTTP(rw, r)
 	}))
 }