Prevent integration test timeout bc. of sudo

Prevent integration test timeout bc. of sudo

Integration tests run by t_client.sh use sudo to run openvpn as root.

If the t_client.sh script is configured to use sudo then the user
must enter the password quickly because t_client assumes a startup
failure if openvpn does not start quick enough.

If the user is not quick enough, then the tests fails.

This change will refresh the sudo timestamp at the start of the script.

Tested on MacOS X & Ubuntu Precise

Signed-off-by: Jens Neuhalfen <jens@neuhalfen.name>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <280154CA-9468-429B-BCAC-DB632C0AFB32@neuhalfen.name>
URL: http://article.gmane.org/gmane.network.openvpn.devel/11622
Signed-off-by: Gert Doering <gert@greenie.muc.de>