* server: remove deprecated UpgradeOldPrivValFile
OldFilePV was deprecated in Tendermint Core v0.28 and will be removed in
upcoming v0.34.5 release.
* remove imports
* Add changelog entries
Co-authored-by: Aleksandr Bezobchuk <aleks.bezobchuk@gmail.com>
Co-authored-by: Alessio Treglia <alessio@tendermint.com>