title: mqtt - mosquito server log shows "Error in poll: Interrupted system call." when receiving a SIGHUP
body: <p>could anyone tell me whether I should be worried about this error:
  "Error in poll: Interrupted system call."</p>
  
  <p>in the mqtt broker mosquito log when sending it a SIGHUP signal to reload its config file ? (in order to take in account a new user/password being created when mosquito runs)</p>
  
  <p>Can I assume that mosquito only reloads its configuration &amp; nothing happen to the established connections &amp; messages under reception or/and publication from various clients when this takes place ?
  Thanks.</p>