Return rendered error result

This solves the "white screen" user get as greeting when people send links to
gitiles, while users do not have any feedback that login should be performed
nor there is a link to login.

Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
Change-Id: Id3854ecc4fbe54e6a69112b0419edd29e8001694
Bug: https://github.com/google/gitiles/issues/145

java/com/google/gitiles/Renderer.java

diff --git a/java/com/google/gitiles/Renderer.java b/java/com/google/gitiles/Renderer.java
index 9ead8bf..bc85290 100644
--- a/java/com/google/gitiles/Renderer.java
+++ b/java/com/google/gitiles/Renderer.java
@@ -60,6 +60,7 @@
           "Common.soy",
           "DiffDetail.soy",
           "Doc.soy",
+          "Error.soy",
           "HostIndex.soy",
           "LogDetail.soy",
           "ObjectDetail.soy",