Log CurrentUser#getEffectiveGroups lazily

This call can be expensive, so we want to perform it only if necessary.

Change-Id: I2c0d4b97fc3ef39a9b6a9a41e14bb1d73e7e05be

java/com/google/gerrit/httpd/restapi/RestApiServlet.java

diff --git a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
index ad2aaf8..f5ece53 100644
--- a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
+++ b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
@@ -331,7 +331,8 @@
               req.getMethod(), req.getRequestURI(), getParameterNames(req));
           logger.atFinest().log("Calling user: %s", globals.currentUser.get().getLoggableName());
           logger.atFinest().log(
-              "Groups: %s", globals.currentUser.get().getEffectiveGroups().getKnownGroups());
+              "Groups: %s",
+              lazy(() -> globals.currentUser.get().getEffectiveGroups().getKnownGroups()));
 
           if (isCorsPreflight(req)) {
             doCorsPreflight(req, res);