make reset tokens only valid for a day

fixes #563

mysql timestamps cannot be null. it will become current timestamp when
set as null

src/userdb.js

@@ -29,7 +29,7 @@ var assert = require('assert'),
     mysql = require('mysql');
 
 var USERS_FIELDS = [ 'id', 'username', 'email', 'fallbackEmail', 'password', 'salt', 'createdAt', 'modifiedAt', 'resetToken', 'displayName',
-    'twoFactorAuthenticationEnabled', 'twoFactorAuthenticationSecret', 'active', 'source', 'role' ].join(',');
+    'twoFactorAuthenticationEnabled', 'twoFactorAuthenticationSecret', 'active', 'source', 'role', 'resetTokenCreationTime' ].join(',');
 
 var APP_PASSWORD_FIELDS = [ 'id', 'name', 'userId', 'identifier', 'hashedPassword', 'creationTime' ].join(',');