If any of the reward tokens doesn't have a liquid pool, it may be impossible to collect rewards

Description:

ShadowStrategyGauge::collectGaugeRewards() swaps all rewards to token0 and token1 through a pool. If this pool doesn't exist or has low liquidity, it may be impossible to swap and collect rewards.

Recommended Mitigation:

Add an alternative mechanism to handle this situation.

0xSimao:

Fixed in #dc55cc7.