Force identifier URL to styling LTR

This is an issue specific to RTL websites whereby all fields, including forms' text-areas, inherit the style directionality of their ancestor elements thus URL fields become right-to-left aligned when they should remain left-to-right aligned since they're almost always in Latin script.

adding the following style directive to openid-selector.css solves this issue:

#openid_username {
	direction: ltr;
}