revise unnecessary 'that' use for 'this'

in this code, 'this' in the scope is correct this.
no need to use 'that'

Author: fediev

site/javascript/garden.js

@@ -158,7 +158,7 @@ Page.prototype = {
             that.onResize();
         });
 
-        that.sections.map();
+        this.sections.map();
         setTimeout(function() {
             that.sections.highlight();
         }, 10);