Update apache template for better seo

Usually you don't want to alias www.domain.tld to domain.tld
You would prefer a 301 http redirection from domain.tld to www.domain.tld to avoid duplicate content penalty from search engine.
see ticket #476 http://trac.i-mscp.net/ticket/476
an even better (ie agnostic) way would be to consider www as any other subdomain, this would let the end user choose if he prefer a alias or a redirection