Wrong button class causes incorrect sizing for landing pages

Problem

Issue #3002541: Buttons in hero section on landingpages moved the classes from a template's wrapping div onto the link using a preprocess hook. While doing this the button class was changed from btn-lg to btn-large. The former is the correct class for a large button (the large one worked in Bootstrap 2.x but does not work in Bootstrap 3.x and is not used in Open Social).

Solution

Change the class back to btn-lg what it should be.

This is a potential breaking change if users have come to rely on the btn-large class for styling this specific element but the button is currently incorrectly styled because it does not have the btn-lg class.