Update base version to 3.4.1-RC1

Author: nicolasstucki

project/Build.scala

@@ -85,7 +85,7 @@ object Build {
 
   val referenceVersion = "3.3.1"
 
-  val baseVersion = "3.4.0-RC1"
+  val baseVersion = "3.4.1-RC1"
 
   // Versions used by the vscode extension to create a new project
   // This should be the latest published releases.