Remove hardcoded localhost for mysql host param

Currently we have hardcoded the mysql database host to be localhost.
This should not be necessary if mysql is configured correctly. As
decisions about database configuration are outside the scope of this
cookbook, removing the hardcoded value.

Change-Id: I13a4ed271229793e634858fc2a41502e11f2fac5
Merge "Remove hardcoded localhost for mysql host param"