Tweaking New Order Email Description

The description for the New Order Email is vague & confusing.

> New order emails are sent when an order is received/paid by a customer.

This makes it seem that getting a new order email has something to do with getting paid but you can receive a new order email without being paid (like checking out with the bank transfer payment gateway).

I tweaked the description to remove the payment wording since that's only confusing.

Ticket: https://woothemes.zendesk.com/agent/#/tickets/99722