Return weighted price also when the price is just one. (i.e. tokens with low liquidity at start)

Adding something like:

if (weightedPrices.length === 1) {
  return weightedPrices[0].price;
}

before the calculation here:

https://github.com/flare-foundation/ftso-v2-example-value-provider/blob/213eb7804cb877de19f34e63c1df50d540fcf36d/src/data-feeds/ccxt-provider-service.ts#L297

works.