test(NETWORK): use POSIX shell for assertion.sh

Make the test 50 more flexible by only requiring a POSIX shell in
`assertion.sh` in the client rootfs.

diff --git a/test/TEST-50-NETWORK/assertion.sh b/test/TEST-50-NETWORK/assertion.sh
index b872f9b5bc14d196f634a1fad389ed87cc4b4500..eaa355208a8860413728eba59f97b587713f14d8 100755 (executable)
--- a/test/TEST-50-NETWORK/assertion.sh
+++ b/test/TEST-50-NETWORK/assertion.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 # Get the output of 'ip addr show' and filter out lo interface
 ip_output=$(ip -o -4 addr show | grep -v ': lo')