Small change in the landing page

This implementation goes to all CRPs

We have made a small improvement into our landing page in order to provide the possibility to login into a Center's and Paltform's MARLO version. See image below:

Although the Center version is not ready yet in our production environment, currently it is being used in our testing environment for CIAT only. In addition, we are in process of understanding how the platforms will use the system.