Point was accessed from multiple goroutines and there was a race on the the internal
cachedFields and cachedName fields. Accessing these fields is unnecessary work as it
requires the point to be unmarshal into Go types and then remarshaled back into protbuf
types. Instead, just send the line protocol version already available on the point via
the protobuf. This avoid accesssing these cached fields and eliminates some extra work.
Possible fix for #4069
ab164c20a2