Prevent data headers crit fail (#2329)
Prevent data headers crit fail (#2329)

* plugins/data_headers: prevent crit fail
msimerson/Haraka,smfreegard/Haraka,smfreegard/Haraka,msimerson/Haraka,smfreegard/Haraka,haraka/Haraka,haraka/Haraka,haraka/Haraka,smfreegard/Haraka,msimerson/Haraka,msimerson/Haraka,haraka/Haraka