added different check to contact-us modal

services/web/public/coffee/main/contact-us.coffee

@@ -21,7 +21,7 @@ define [
 			$scope.sending = true
 			ticketNumber = Math.floor((1 + Math.random()) * 0x10000).toString(32)
 			message = $scope.form.message
-			if $scope.form.project_url
+			if $scope.form.project_url?
 				message	= "#{message}\n\n project_url = #{$scope.form.project_url}" 
 			params =
 				email: $scope.form.email