Add support for aliases of virtualserver

[MurzNN]

When I create alias of domain, in apache all creates normally, but nginx are configured to separate folder, that don't exists.
How to reproduce:

1. Create in virtualmin new virtualserver example.com
   In nginx example.com.conf you will see:
   access_log /home/example.com/logs/example.com.access.log;
error_log /home/example.com/logs/example.com.error.log;
2. Create via virtualmin the alias of example.com, named example2.com
   You will see in example2.com.conf:
access_log /home/example.com/domains/example2.com/logs/example2.com.access.log;
error_log /home/example.com/domains/example2.com/logs/example2.com.error.log;

But if you create the aliases (not sub-servers), those folders will not created and you will got the error on restarting nginx:
# nginx -t
the configuration file /etc/nginx/nginx.conf syntax is ok

configuration file /etc/nginx/nginx.conf test failed

Can you fix this problem?

[MurzNN]

Instead of creating new nginx example2.com.conf will better to add domain aliases in already exists example.com.conf, like in the apache:
ServerName example.com
ServerAlias example2.com