Revert "Bump yang tools version to 2.4"
This reverts commit 5193cb736c41d52f6007e7e2bdfd619b7598604f.
Change-Id: If061ca507f702f161fa112188abd26aa4924618d
diff --git a/tools/dev/bin/patch-yang-libs b/tools/dev/bin/patch-yang-libs
index 2686836..fd119b3 100755
--- a/tools/dev/bin/patch-yang-libs
+++ b/tools/dev/bin/patch-yang-libs
@@ -3,8 +3,8 @@
# Patches lib/BUCK file to use locally built YANG tools.
# -----------------------------------------------------------------------------
-BVER=2.4
-SVER=2.5-SNAPSHOT
+BVER=2.3.1
+SVER=2.4-SNAPSHOT
YANG_TOOLS_ROOT=${YANG_TOOLS_ROOT:-~/onos-yang-tools}