Network TX drops now non-zero after update to RL9.6

[gerry666uk]

@onthebeatenpath

Switching between RL9.5 and RL9.6 is ALWAYS 0 TX drops for RL9.5 and non-zero for RL9.6.

One possibility is that 9.5 is giving inaccurate results, and 9.6 is showing the real situation (unlikely but possible), so maybe try using something other than netstat, first on 9.5 and then on 9.6, some raw kernel counter or /proc filesystem, or some other tool.