test: release tests with v3.2+

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

test

@@ -170,7 +170,7 @@ function grpcproxy_pass {
 function release_pass {
 	rm -f ./bin/etcd-last-release
 	# to grab latest patch release; bump this up for every minor release
-	UPGRADE_VER=$(git tag -l --sort=-version:refname "v3.1.*" | head -1)
+	UPGRADE_VER=$(git tag -l --sort=-version:refname "v3.2.*" | head -1)
 	if [ -n "$MANUAL_VER" ]; then
 		# in case, we need to test against different version
 		UPGRADE_VER=$MANUAL_VER