[Desktop] Blank rewards page

[janypiotrowski]

Description

Brave Rewards (brave://rewards/) is a blank page. Discovered by clicking on "Verify Wallet" button in BAT icon dropdown.

Steps to Reproduce

1. Click on BAT icon in URL bar
2. Click on "Verify Wallet"
3. Alternatively, just go to brave://rewards/

Actual result:

## Expected result: Rewards settings and wallet verification flow.

Reproduces how often:

Every time.

Brave version (brave://version info)

Brave	1.11.83 Chromium: 83.0.4103.116 (Official Build) beta (64-bit)
Revision	8f0c18b4dca9b6699eb629be0f51810c24fb6428-refs/branch-heads/4103@{#716}
OS	macOS Version 10.15.4 (Build 19E287)

Version/Channel Information:

• Can you reproduce this issue with the current release? No
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the dev channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information: