Properly remove DHCP lease file upon disconnection
Add the following line to /etc/profile:
PRE_UP=' [ -e /var/lib/dhcpcd/dhcpcd-wlan0.lease ] && rm /var/lib/dhcpcd/dhcpcd-wlan0.lease '
Add the following line to /etc/profile:
PRE_UP=' [ -e /var/lib/dhcpcd/dhcpcd-wlan0.lease ] && rm /var/lib/dhcpcd/dhcpcd-wlan0.lease '