cligen: update submodule

Signed-off-by: Alexander Sosedkin <asosedkin@redhat.com>

diff --git a/cligen b/cligen
index 59911854af60377b045ec8db88ae969b5bad1f66..f6ff7a8611d67a4ffa8ad17d40bbc6cef348cddb 160000 (submodule)
--- a/cligen
+++ b/cligen
@@ -1 +1 @@
-Subproject commit 59911854af60377b045ec8db88ae969b5bad1f66
+Subproject commit f6ff7a8611d67a4ffa8ad17d40bbc6cef348cddb