Fix Single Provider in the FallbackProvider Array

[samuelexferri]

Fix the corner case where if only one provider was passed in the FallbackProvider array it would cause errors even simply on the provider.getBlockNumber().

Fix the issue #3745

[samuelexferri]

@ricmoo

[ng-tony]

I have a similar issue, but it fails whenever there is an odd number of providers.
I think the bug is from line 255

    const mid = values.length / 2; //When values.length is odd mid is a floating point

    // Odd-length; take the middle value
    if (values.length % 2) { return values[mid]; } //Indexing by a float

[ricmoo]

Please do not modify generated files, as it makes the diff to complicated. You should only need to modify files in the /src.ts/ folder.

[samuelexferri]

Ok! Only one line has changed. I added Math.floor() function to the float variable "mid".

[ricmoo]

Lol! Awesome! Yes, that makes sense. I will get that change in for the next patch release. :)

[ricmoo]

Merged into v6.0.4.

Thanks! :)