Delete unused static const

[sashamelentyev]

This PR is sponsored by Evrone

[codecov]

Codecov Report

Merging #2830 (2f709e3) into master (a46dee3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2830   +/-   ##
=======================================
  Coverage   98.75%   98.75%           
=======================================
  Files          41       41           
  Lines        3063     3063           
=======================================
  Hits         3025     3025           
  Misses         26       26           
  Partials       12       12           

Flag	Coverage Δ
go-1.13	98.75% <ø> (ø)
go-1.14	98.59% <ø> (ø)
go-1.15	98.59% <ø> (ø)
go-1.16	98.59% <ø> (ø)
macos-latest	98.75% <ø> (ø)
nomsgpack	98.74% <ø> (ø)
ubuntu-latest	98.75% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
tree.go	100.00% <ø> (ø)

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[sashamelentyev]

@appleboy @thinkerou

[appleboy]

@alexander-melentyev Thanks.