Issue with quotes - bugfix

Hello,

another report for plugin author.

When you enter some quotes into the messages text like:

it's so nice!

...and then you send the email without entering subject, it returns with a message, that you need to fill in all the fields. And the textarea with message text has a backslash in front of the quote, like this:

it\'s so nice!

I had to add stripslashes where the print of the $_POST['email_content'] in textarea tag is.

Please include this fix in new version, or find a better one.

Thanks,
Martin