Acunetix test failed

Hi, captcha team

I found some errors during acunetix trial test, we can't see queries what executes this errors, but we can provide patches to fix this problems:

1. PDOException: SQLSTATE[22001]: String data, right truncated: 1406 Data too long for column 'sid' at row 1: INSERT INTO {captcha_sessions} (uid, sid, ip_address, timestamp, form_id, solution, status, attempts) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => http://some-inexistent-website.acu/some_inexistent_file_with_long_name?.jpg [:db_insert_placeholder_2] => XXXXXXX [:db_insert_placeholder_3] => 1435161078 [:db_insert_placeholder_4] => sms_login_register_form [:db_insert_placeholder_5] => ffda4841ba148afa4eb9ed339ba5a326 [:db_insert_placeholder_6] => 0 [:db_insert_placeholder_7] => 0) in function _captcha_generate_captcha_session() (string 174 in file/.../sites/all/modules/captcha/captch
2. CAPTCHA validation error: unknown CAPTCHA session ID (0)
3. PDOException: in function _captcha_generate_captcha_session() (string 174 in /..../sites/all/modules/captcha/captcha.inc).

in all login/register forms we use image captcha with standart settings