ref(jumbotron):removed jumbotron styles (#21396)

Author: robinrendle

src/sentry/static/sentry/less/includes/bootstrap/bootstrap.less

@@ -33,7 +33,6 @@
 @import 'pager.less';
 @import 'labels.less';
 @import 'badges.less';
-@import 'jumbotron.less';
 @import 'thumbnails.less';
 @import 'alerts.less';
 @import 'progress-bars.less';

src/sentry/static/sentry/less/includes/bootstrap/jumbotron.less

@@ -467,17 +467,6 @@
 
 @pager-disabled-color: @pagination-disabled-color;
 
-//== Jumbotron
-//
-//##
-
-@jumbotron-padding: 30px;
-@jumbotron-color: inherit;
-@jumbotron-bg: @gray-lighter;
-@jumbotron-heading-color: inherit;
-@jumbotron-font-size: ceil((@font-size-base * 1.5));
-@jumbotron-heading-font-size: ceil((@font-size-base * 4.5));
-
 //== Form states and alerts
 //
 //## Define colors for form feedback states and, by default, alerts.