waiting when check_fault_nodes return NO_INIT

[majieyue]

What changes were proposed in this pull request?

check_fault_nodes will cover NetworkFailureReason.NO_INIT situation

Why are the changes needed?

check_fault_nodes will return None and the reason is NO_INIT. client should keep waiting.

Does this PR introduce any user-facing change?

No

How was this patch tested?

UT

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 81.19%. Comparing base (7ba180c) to head (8ed6ed7).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
dlrover/python/elastic_agent/master_client.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1440      +/-   ##
==========================================
- Coverage   81.20%   81.19%   -0.01%     
==========================================
  Files         238      238              
  Lines       23169    23173       +4     
==========================================
+ Hits        18815    18816       +1     
- Misses       4354     4357       +3     

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