update timestamp when replacing a record in the staged table. required for issue #430

lib/db/mysql.js

@@ -219,7 +219,7 @@ exports.stageUser = function(email, cb) {
   var secret = secrets.generate(48);
   // overwrite previously staged users
   client.query('INSERT INTO staged (secret, new_acct, email) VALUES(?,TRUE,?) ' +
-               'ON DUPLICATE KEY UPDATE secret=?, existing="", new_acct=TRUE',
+               'ON DUPLICATE KEY UPDATE secret=?, existing="", new_acct=TRUE, ts=NOW()',
                [ secret, email, secret],
                function(err) {
                  if (err) {
@@ -317,7 +317,7 @@ exports.stageEmail = function(existing_email, new_email, cb) {
   var secret = secrets.generate(48);
   // overwrite previously staged users
   client.query('INSERT INTO staged (secret, new_acct, existing, email) VALUES(?,FALSE,?,?) ' +
-               'ON DUPLICATE KEY UPDATE secret=?, existing=?, new_acct=FALSE',
+               'ON DUPLICATE KEY UPDATE secret=?, existing=?, new_acct=FALSE, ts=NOW()',
                [ secret, existing_email, new_email, secret, existing_email],
                function(err) {
                  if (err) {