director: Make sure HOST-RESET-USERS isn't used with max_moving_users=0 The reset command would just hang in that case. doveadm would never have sent this, so this is just an extra sanity check.

#ifndef BACKTRACE_STRING_H
#define BACKTRACE_STRING_H

/* Returns 0 if ok, -1 if failure. */
int backtrace_append(string_t *str);
int backtrace_get(const char **backtrace_r);

#endif