TT#82852 Add missing working_dir variable

This variable is required to locate check-for-network script.

Change-Id: I7b5792acab6134a47cdbea6793065d674e47a67f
(cherry picked from commit 73327b10f0)

templates/scripts/includes/network_configuration.sh

@@ -2,6 +2,8 @@
 
 set -e
 
+working_dir="$(dirname "$0")"
+
 while ! "${working_dir}/check-for-network" ; do
   /usr/sbin/netcardconfig
 done