change six pack key and add into default settings

services/web/app/views/layout.jade

@@ -57,7 +57,7 @@ html(itemscope, itemtype='http://schema.org/Product')
 			window.sharelatex = {
 				siteUrl: '#{settings.siteUrl}',
 				jsPath:  '#{jsPath}',
-				sixpackDomain: '#{settings.sixpackDomain}'
+				sixpackDomain: '#{settings.sixpack.domain}'
 			};
 			window.systemMessages = !{JSON.stringify(systemMessages).replace(/\//g, '\\/')};
 			window.ab = {}

services/web/config/settings.defaults.coffee

@@ -353,6 +353,8 @@ module.exports =
 		
 	]
 
+	sixpack:
+		domain:"http://45.79.157.156:5000"
 	# ShareLaTeX Server Pro options (https://www.sharelatex.com/university/onsite.html)
 	# ----------