fix f5 bigip trunks div by 0 error (#977)
fix f5 bigip trunks div by 0 error (#977)

Closes https://github.com/centreon/centreon-plugins/issues/976
Sims24/centreon-plugins,Sims24/centreon-plugins,Tpo76/centreon-plugins,wilfriedcomte/centreon-plugins,centreon/centreon-plugins,centreon/centreon-plugins,Tpo76/centreon-plugins