[skip changelog] fix(cli): print RebroadcastBackoffExponent in lotus f3 manifest

[hanabi1224]

Related Issues

(Came across this while implementing ChainSafe/forest#4937)
RebroadcastBackoffExponent seems to be dropped in lotus f3 manifest output.

Proposed Changes

Print GPBFT Rebroadcast Backoff Exponent: 1.3 line in lotus f3 manifest output

Additional Info

Output with the change

➜  lotus git:(master) ✗ ./lotus f3 manifest
Manifest:
  Protocol Version:     4
  Paused:               false
  Initial Instance:     0
  Initial Power Table:  bafy2bzaceab236vmmb3n4q4tkvua2n4dphcbzzxerxuey3mot4g3cov5j3r2c
  Bootstrap Epoch:      2081674
  Network Name:         calibrationnet
  Ignore EC Power:      false
  Committee Lookback:   10
  Catch Up Alignment:   15s

  GPBFT Delta:                        6s
  GPBFT Delta BackOff Exponent:       2
  GPBFT Max Lookahead Rounds:         5
  GPBFT Rebroadcast Backoff Base:     6s
  GPBFT Rebroadcast Backoff Exponent: 1.3
  GPBFT Rebroadcast Backoff Spread:   0.1
  GPBFT Rebroadcast Backoff Max:      1m0s

  EC Period:            30s
  EC Finality:          900
  EC Delay Multiplier:  2
  EC Head Lookback:     0
  EC Finalize:          true

  Certificate Exchange Client Timeout:    10s
  Certificate Exchange Server Timeout:    1m0s
  Certificate Exchange Min Poll Interval: 30s
  Certificate Exchange Max Poll Interval: 2m0s

Checklist

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• Commits have a clear commit message.
• PR title conforms with contribution conventions
• Update CHANGELOG.md or signal that this change does not need it per contribution conventions
• New features have usage guidelines and / or documentation updates in
  • Lotus Documentation
  • Discussion Tutorials
• Tests exist for new functionality or change in behavior
• CI is green