legs_controller.rb: fix rendering issue when validation fails

Chrome and Firefox will respect HTML5 tags, so the server-side validation is superfluous.
For IE unfortunately, it is still required. The code was broken as it didn't re-populate the necessary
variables.

Signed-off-by: diditclear <didyourupgradeclear@gmail.com>
sign_in: explain why it is a good idea to log-in

Signed-off-by: diditclear <didyourupgradeclear@gmail.com>