Changing AVAX-USDC.e to 10x

USDC.e is a new stablecoin available on Avalanche and is crucial in the ecosystem. Pangolin should strive to have the most liquidity for USDC.e. It currently only has a 1x multiplier which is not competitive.

We have already increase USDT.e and DAI.e to 10x. We should increase USDC.e to 10x as well.

In line with the forum post https://gov.pangolin.exchange/t/changing-key-pair-reward-multipliers/1705

Proposed change: AVAX -USDC.e to 10x