Revert "Upgrading to stc 2.3"

This reverts commit e0ee56cecfbd0029f18938fe4d2f35d1242fd772.

Change-Id: I348743fa1b409df1ec912e310207b67591b2fc39
diff --git a/tools/test/bin/stc b/tools/test/bin/stc
index cb5f32a..d7ddc7c 100755
--- a/tools/test/bin/stc
+++ b/tools/test/bin/stc
@@ -5,7 +5,7 @@
 
 . $ONOS_ROOT/tools/build/envDefaults
 
-VER=${STC_VERSION:-2.3}
+VER=${STC_VERSION:-2.2}
 JAR=~/.m2/repository/org/onosproject/onos-stc/$VER/onos-stc-$VER.jar
 SCENARIOS=$ONOS_ROOT/tools/test/scenarios