Update the tutorial to use the best way to load rules_appengine.

--
Change-Id: Ide481cbbd0d404aab144833efc09c0b48a8b968a
Reviewed-on: https://cr.bazel.build/8092
PiperOrigin-RevId: 143589969
MOS_MIGRATED_REVID=143589969
diff --git a/site/versions/master/docs/tutorial/backend-server.md b/site/versions/master/docs/tutorial/backend-server.md
index 137a97a..b22b8b5 100644
--- a/site/versions/master/docs/tutorial/backend-server.md
+++ b/site/versions/master/docs/tutorial/backend-server.md
@@ -69,10 +69,11 @@
 Add the following to your `WORKSPACE` file:
 
 ```python
-git_repository(
+http_archive(
     name = "io_bazel_rules_appengine",
-    remote = "https://github.com/bazelbuild/rules_appengine.git",
-    tag = "0.0.3",
+    sha256 = "f4fb98f31248fca5822a9aec37dc362105e57bc28e17c5611a8b99f1d94b37a4",
+    strip_prefix = "rules_appengine-0.0.6",
+    url = "https://github.com/bazelbuild/rules_appengine/archive/0.0.6.tar.gz",
 )
 load("@io_bazel_rules_appengine//appengine:appengine.bzl", "appengine_repositories")
 appengine_repositories()