Previously it incorrectly applied xFilesFactor, if it's value equal to 0.
This commit properly handles this case and returns result according to
the graphite documentation:
`xFilesFactor follows the same semantics as in Whisper storage schemas. Setting it to 0 (the default) means that only a single value in the series needs to be non-null for it to be considered non-empty, setting it to 1 means that all values in the series must be non-null. A setting of 0.5 means that at least half the values in the series must be non-null.`
Signed-off-by: f41gh7 <nik@victoriametrics.com>
Co-authored-by: Evgeniy Negriy <einegriy@avito.ru>
(cherry picked from commit d27dfac5c6)
98fe1950a1