Fix #709 collaborator invite email

Author: Ilya Radchenko

lib/email.js

@@ -119,8 +119,8 @@ exports.send_invite_collaborator_new_user = function(inviter, email, code, url)
     strider_server_name: config.server_name
   };
 
-  var body_text = text.collaborator_invite_new(jade_variables);
-  var body_html = html.collaborator_invite_new(jade_variables);
+  var body_text = text.collaborator_invite_new_user(jade_variables);
+  var body_html = html.collaborator_invite_new_user(jade_variables);
 
   mailer.send(to,subject,body_text,body_html);