[BUGFIX] Expose the correct external IP of GIE.

[lidongze0629]

What do these changes do?

• Check GIE gremlin service external ip is null by for loop.
• fix the stream log failed problem when the GIE manager image is not exist.

[codecov-io]

Codecov Report

Merging #69 (704515a) into main (5c9a222) will decrease coverage by 0.03%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main      #69      +/-   ##
==========================================
- Coverage   78.04%   78.01%   -0.04%     
==========================================
  Files          49       49              
  Lines        4473     4475       +2     
==========================================
  Hits         3491     3491              
- Misses        982      984       +2     

Impacted Files	Coverage Δ
python/graphscope/deploy/kubernetes/cluster.py	73.70% <0.00%> (-0.56%)	⬇️

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