fixed a failure

application/libraries/Aauth.php

@@ -239,13 +239,13 @@ class Aauth {
 	 	if($this->config_vars['totp_active'] == TRUE){
 			$query = null;
 			$query = $this->aauth_db->where($db_identifier, $identifier);
-			$query = $this->aauth_db->where('totp_secret !=', '');
 			$query = $this->aauth_db->get($this->config_vars['users']);
+			$totp_secret =  $query->row()->totp_secret;
 			if ($query->num_rows() > 0 AND !$totp_code) {
 				$this->error($this->CI->lang->line('aauth_error_totp_code_required'));
 				return FALSE;
-			}else if ($query->num_rows() > 0 AND $totp_code) {
-				$totp_secret =  $query->row()->totp_secret;
+			}else {
+				if(!empty($totp_secret)){
 					$ga = new PHPGangsta_GoogleAuthenticator();
 					$checkResult = $ga->verifyCode($totp_secret, $totp_code, 0);
 					if (!$checkResult) {
@@ -254,6 +254,7 @@ class Aauth {
 					}
 				}
 			}
+	 	}
 		
 		// if email and pass matches and not banned
 		if ( $query->num_rows() > 0 ) {