Fix risk gauge

[jordajm]

The risk gauge on the Margin Account page is not working correctly. Probably because the algorithm is not correct.

Look at this for how it should work:
https://www.binance.com/en-IN/support/faq/360030493931

DrO says:
When margin level≤1.15, our system will trigger the liquidation engine and we will send you a notification by mail, text message and internal message to inform you that all assets will be liquidated to pay back the interest and loan.
1.15 is when we trigger
but when we get on faster chains, we will probably reduce to 1.1
Ethereum is too slow and clogged for us to do 1.1

[cawthorne]

fixed by:
#154