Bump to Gerrit v2.16.8 API

Change-Id: Iad6e464b67a1c031b6e632ff3a9414248a3d7b94

build.sbt

diff --git a/build.sbt b/build.sbt
index 8b8b267..f0f4745 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,6 +1,6 @@
 enablePlugins(GitVersioning)
 
-val gerritApiVersion = "2.16"
+val gerritApiVersion = "2.16.8"
 
 val pluginName = "analytics"