x/sequencers: document and fix insufficient bond check in bond reduction completion

[danwt]

dymension/x/sequencer/keeper/unbond.go

Lines 156 to 163 in acd9d13

	if seq.Tokens.IsAllLT(sdk.NewCoins(reduction.UnbondAmount)) {
	return errorsmod.Wrapf(
	types.ErrInsufficientBond,
	"sequencer does not have enough bond to reduce insufficient bond: got %s, reducing by %s",
	seq.Tokens.String(),
	reduction.UnbondAmount.String(),
	)
	}

#1031 (comment)

[danwt]

superseded by #1328