We don't show currency conversions for Sepolia testnet

[adonesky1]

Even with Show conversion on test networks setting turned on we don't show conversions. I vaguely remember that we hardcoded something for getting conversions for testnet eth somewhere

[emedvedev]

This should be fixed when MetaMask/core#1041 is merged in, from what I can tell. You'd need to add SepoliaETH to TESTNET_TICKER_SYMBOLS so that the conversion rate would fall back to ETH, and 1041 includes that change.

Tried to fix the bug myself and saw that there's a solution already. :)