A user should be redirected to home page if logged in instead of the login page

SAME AS (LUI-60)https://issues.openmrs.org/browse/LUI-60

Reproducing issue:

• Setup an instance of openmrs legacy application (not reference application)
• login and access http://188.226.232.194:8080/openmrs/login.htm (change path accordingly)
• that page needs not to show up a login form since user is already signed in

Assignment:

• Check if user is logged in on accessing that login page and only render it if user is logged out
• Redirect to either previous page or home page accordingly if user is logged in