Set Gerrit to v3.4.0-rc0

Change-Id: I49888e1845b96a16fbc2f7f4dc30a3365a589d14

build.sbt

diff --git a/build.sbt b/build.sbt
index 306c326..55edb29 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,6 +1,6 @@
 enablePlugins(GitVersioning)
 
-val gerritApiVersion = "3.4.0-SNAPSHOT"
+val gerritApiVersion = "3.4.0-rc0"
 
 val pluginName = "analytics"