[bugfix] Fix insufficient synchronization on ping variable
[bugfix] Fix insufficient synchronization on ping variable

RemiKoutcherawy/exist,hungerburg/exist,wolfgangmm/exist,opax/exist,wolfgangmm/exist,wolfgangmm/exist,eXist-db/exist,RemiKoutcherawy/exist,windauer/exist,olvidalo/exist,adamretter/exist,RemiKoutcherawy/exist,olvidalo/exist,opax/exist,ljo/exist,ljo/exist,ambs/exist,dizzzz/exist,opax/exist,opax/exist,hungerburg/exist,olvidalo/exist,eXist-db/exist,adamretter/exist,lcahlander/exist,hungerburg/exist,dizzzz/exist,lcahlander/exist,hungerburg/exist,wolfgangmm/exist,ljo/exist,adamretter/exist,windauer/exist,ljo/exist,lcahlander/exist,wolfgangmm/exist,eXist-db/exist,olvidalo/exist,adamretter/exist,RemiKoutcherawy/exist,windauer/exist,wolfgangmm/exist,eXist-db/exist,ljo/exist,adamretter/exist,windauer/exist,olvidalo/exist,dizzzz/exist,lcahlander/exist,windauer/exist,ambs/exist,lcahlander/exist,opax/exist,RemiKoutcherawy/exist,dizzzz/exist,windauer/exist,ambs/exist,hungerburg/exist,ljo/exist,eXist-db/exist,ambs/exist,dizzzz/exist,eXist-db/exist,ambs/exist,lcahlander/exist,dizzzz/exist,RemiKoutcherawy/exist,ambs/exist,adamretter/exist