Kill dhclient when reconfig interfaces (#683)

Author: taoyl-ms

files/image_config/interfaces/interfaces-config.sh

@@ -1,5 +1,6 @@
 #!/bin/bash
 
 sonic-cfggen -m /etc/sonic/minigraph.xml -t /usr/share/sonic/templates/interfaces.j2 >/etc/network/interfaces
+[ -f /var/run/dhclient.eth0.pid ] && kill `cat /var/run/dhclient.eth0.pid` && rm -f /var/run/dhclient.eth0.pid
 service networking restart
 ifdown lo && ifup lo