delete runtest/nw_under_ns

nw_under_ns.sh test was rewritten and moved to runtest/containers scenario file

Signed-off-by: Wenzhong Sun <wenzhong.sun@intel.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
diff --git a/runtest/nw_under_ns b/runtest/nw_under_ns
deleted file mode 100644
index 54217a6..0000000
--- a/runtest/nw_under_ns
+++ /dev/null
@@ -1,2 +0,0 @@
-# Network testcases under containers
-network_namespace	nw_under_ns.sh