Cannot collect VMWare when maxQueryMetrics is -1.

Steps to reproduce:

1. Set config.vpxd.stats.maxQueryMetrics to -1 as https://kb.vmware.com/s/article/2107096 suggest in solution step 7.
2. Discover of VSphere

Result:
zabbix_server.log shows:

error reason for "VSpherehost:vmware.cluster.discovery[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
error reason for "VSpherehost:vmware.hv.discovery[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
error reason for "VSpherehost:vmware.vm.discovery[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
error reason for "VSpherehost:vmware.eventlog[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
error reason for "VSpherehost:vmware.fullname[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
error reason for "VSpherehost:vmware.version[\{$URL}]" changed: Cannot convert maxQueryMetrics from -1.
Expected:
We should be able to collect VMWare when the limit on query size is disabled or unlimited.

It should also collect when the limit is not specified (config.vpxd.stats.maxQueryMetrics not set)