Login Image Resized Incorrectly in v3.8

WordPress v3.8 sets the size of the login image using:
background-size: 80px 80px;

This could be fixed if the plugin added the following CSS:

.login h1 a {
background-size: auto !important;
width: auto !important;

Conditional logic would need to be added to add this CSS only if a custom login image were added.