Leaderboard crashes when node version is unknown

The leaderboard crashes when the fork observer returns node info with an unknown version string, because getVersionNumber assumes the string contains `:` and ends up indexing into undefined.

Reference: https://github.com/bitcoin-dev-project/warnet-web/blob/aec0175bf61f5fe4b4d9880ac4e9c38dafe64eb0/src/helpers/index.ts#L73

```
export const getVersionNumber = (version: string) => {
// get the version number from the version string
return version.split(":")[1].split("/")[0].split("(")[0] ?? false;
}
```