Stale split ratios in UniversalBuyback
The `gulp` and `pendingBurning` functions of the `UniversalBuyback` contract use the hardcoded, constant values of `DEFAULT_REWARD_BUYBACK1_SHARE` and `DEFAULT_REWARD_BUYBACK2_SHARE` to determine the ratio the trade value is split with.\\nConsequently, any call to `setRewardSplit` to set a new ratio will be ineffective but still result in a `ChangeRewardSplit` event being emitted. This event can deceive system operators and users as it does not reflect the correct values of the contract.\\n```\\nuint256 \\_amount1 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK1\\_SHARE) / 1e18;\\nuint256 \\_amount2 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK2\\_SHARE) / 1e18;\\n```\\n\\n```\\nuint256 \\_amount1 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK1\\_SHARE) / 1e18;\\nuint256 \\_amount2 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK2\\_SHARE) / 1e18;\\n```\\n
Instead of the default values, `rewardBuyback1Share` and `rewardBuyback2Share` should be used.
```\\nuint256 \\_amount1 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK1\\_SHARE) / 1e18;\\nuint256 \\_amount2 = \\_balance.mul(DEFAULT\\_REWARD\\_BUYBACK2\\_SHARE) / 1e18;\\n```\\n