parseInt member count, use getMemberCount in install js

src/groups.js

@@ -363,7 +363,12 @@ var async = require('async'),
 	};
 
 	Groups.getMemberCount = function(groupName, callback) {
-		db.getObjectField('group:' + groupName, 'memberCount', callback);
+		db.getObjectField('group:' + groupName, 'memberCount', function(err, count) {
+			if (err) {
+				return callback(err);
+			}
+			callback(null, parseInt(count, 10));
+		});
 	};
 
 	Groups.isMemberOfGroupList = function(uid, groupListKey, callback) {

src/install.js

@@ -294,8 +294,11 @@ function enableDefaultTheme(next) {
 
 function createAdministrator(next) {
 	var Groups = require('./groups');
-	Groups.get('administrators', {}, function (err, groupObj) {
-		if (!err && groupObj && groupObj.memberCount > 0) {
+	Groups.getMemberCount('administrators', function (err, memberCount) {
+		if (err) {
+			return next(err);
+		}
+		if (memberCount > 0) {
 			process.stdout.write('Administrator found, skipping Admin setup\n');
 			next();
 		} else {