Cannot recover from corrupted wallet

[btlechowski]

Follow up from #2183

Steps to Reproduce

1. enable rewards
2. close browser
3. modify ledger_state by deleting walletInfo content
   "walletInfo":{}
4. Restart

Actual result:

• The expected UI error message is not shown.
• The wallet remains in corrupted state.
• Cannot claim grant.

Expected result:

-show error message

-able recover the wallet
-able to claim grant

Reproduces how often:

always

Brave version (brave://version info)

Brave	0.58.12 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows 7

cc @NejcZdovc @brave/legacy_qa

[LaurenWags]

Reproduces on macOS

Brave	0.58.12 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Mac OS X

[NejcZdovc]

this will be fixed with brave/brave-core#1086. So the next 0.58 build should fix it

[btlechowski]

Verification passed on

Brave	0.58.14 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Windows 7

Used STR from OP.

Verified passed with

Brave	0.58.14 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Mac OS X

• Verified STR from description.

Verification PASSED on Ubuntu 18.04.1 x64 using the following build:

Brave	0.58.14 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Linux

• verified that there's a Recover Now! link that opens chrome://rewards/#
• ensured that you can recover a wallet without any issues
• ensured that the correct address is being displayed under ledger_state and brave://rewards