Correct image URL to be absolute within repository

Change-Id: I4641276929062da891cba0f0bf7977193739ce38
diff --git a/navbar.md b/navbar.md
index 76d192b..e87f3f4 100644
--- a/navbar.md
+++ b/navbar.md
@@ -8,4 +8,4 @@
 * [Reviews](https://gerrit-review.googlesource.com/#/q/status:open+project:gerrit)
 
 [home]: /index.md
-[logo]: images/diffy45.png
+[logo]: /images/diffy45.png