Update cloud-set-guest-password.in
Adaptation of the original script to be able to work with netplan, network manager and ifupdown.
Changes have been tested in Cloudstack V 4.13 with the following operating systems and network providers :
Ubuntu 16.04 with ifupdown (/etc/network/interfaces)
Ubuntu 18.04 with netplan
Ubuntu 20.04 with netplan
Debian 10 with ifupdown (/etc/network/interfaces)
Debian 9 with ifupdown (/etc/network/interfaces)
CentOS 8 with network manager (/etc/sysconfig/network-scripts/ifcfg-eth0)
CentOS 7 with network manager (/etc/sysconfig/network-scripts/ifcfg-eth0)
Create a new vm from template with password feature enabled and log in the vm with provided password.
Stop the vm, change the password with the feature, start the vm and log in the vm with provided password.
The exit status of wget was not checked properly since it would
check the exit status of the 'echo' command.
Also fix some indentation in the script and remove whitespace
