SNMP Uptime is not always ignored for spikekills

[netniV]

Describe the bug

When getting system host statistics, the SMNP host time, the alternate .1.3.6.1.6.3.10.2.1.3.0 is not ignored by SpikeKill and should be consistent with the older uptime 1.3.6.1.2.1.1.3.0

[TheWitness]

Good catch. Same with spine?

[netniV]

Yup had the same on spine, I made some SNMP related changes to availability. They seem to be working for me, and both spine and lib/ping now use the exact same logic for availability check.