cli: Fix error in orchestrator registration

[leszko]

What does this pull request do? Explain your changes. (required)

After the handlers refactoring PR, user may see an error message while registering the orchestrator.

Specific updates (required)

How did you test each of these updates (required)

Does this pull request close any open issues?

Checklist:

• Read the contribution guide
• make runs successfully
• All tests in ./test.sh pass
• README and other documentation updated
• Pending changelog updated

[codecov]

Codecov Report

Merging #2390 (38f5a5a) into master (1e5ce2a) will increase coverage by 0.01541%.
The diff coverage is 0.00000%.

@@                 Coverage Diff                 @@
##              master       #2390         +/-   ##
===================================================
+ Coverage   54.50763%   54.52304%   +0.01541%     
===================================================
  Files             93          93                 
  Lines          19467       19467                 
===================================================
+ Hits           10611       10614          +3     
+ Misses          8267        8264          -3     
  Partials         589         589                 

Impacted Files	Coverage Δ
cmd/livepeer_cli/wizard.go	0.00000% <0.00000%> (ø)
discovery/db_discovery.go	65.97222% <0.00000%> (+1.04165%)	⬆️

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