Invalid bytes string error fixed

[nivida]

Description

If the response is '0x' then it will return 'null'.

Fixes #2527 #2499 #2444

Type of change

• Bug fix

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no warnings.
• I have updated or added types for all modules I've changed
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run test in the root folder with success and extended the tests if necessary.
• I ran npm run build in the root folder and tested it in the browser and with node.
• I ran npm run dtslint in the root folder and tested that all my types are correct
• I have tested my code on an ethereum test network.

[coveralls]

Coverage remained the same at 95.692% when pulling 99d7544 on issue/2527 into 5dccc72 on 1.0.

[coveralls]

Coverage remained the same at 95.692% when pulling 99d7544 on issue/2527 into 5dccc72 on 1.0.

[coveralls]

Coverage remained the same at 95.692% when pulling 99d7544 on issue/2527 into 5dccc72 on 1.0.

[MacdaraD]

I am still getting this error running on a local node with the most up to date versions of geth, nodejs and web3. I understand that if there's any hope of you solving my problem you'll need more information than that so let me know what you may need and I'll supply it (provided you have time to answer me).