Update mysql.rb
Setting $drupal_hash_salt back to its default value of ''.
Merge pull request #15 from tannerjfco/master

Fixes setting a mysql default.
Merge pull request #18 from rickmanelius/drupal_hash_salt

Setting $drupal_hash_salt back to its default value of ''.
Merge pull request #20 from timodwhit/master

Allows for d6 sites to be installed.