SEGV in gearmand

[Xeno]

In libgearman-server/server.cc there is a gearmand_log_debug line that tries to print the server_job->function on a GEARMAN_COMMAND_WORK_EXCEPTION.
server_job is sometimes NULL, and since the check for server_job == NULL is after the gearmand_log_debug, gearmand crashes.

I think it should be like this:
[code]
      if (server_job == NULL)
      {
        return _server_error_packet(GEARMAN_DEFAULT_LOG_PARAM, server_con, GEARMAN_JOB_NOT_FOUND,
                                    gearman_literal_param("An exception was received for a job that does not exist"));
      }
      gearmand_log_debug(GEARMAN_DEFAULT_LOG_PARAM,
                         "Exception being sent from: %.*s(%lu)",
                         server_job->function->function_name_size, server_job->function->function_name, server_job->function->function_name_size);
[/code]