Bump minor version post VOLTHA2.4 branch out

Change-Id: I00b5cc4f023f98cb9719b8aa6816dcb81473c6c1
diff --git a/VERSION b/VERSION
index 35cee72..69fa968 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.4.3
+2.5.0-dev