Optimize retry mechanism in invokeEndpoint

[sameersubudhi]

What was the problem?

This PR resolves #1904

How was it solved?

• Tweak the setting in client.js

How was it tested?

• Locally against the testnet
  • Block indexing time is now reduced to ~50-150ms from over ~1-1.5sec. Verified with console.time

[codecov]

Codecov Report

Merging #1905 (5001c66) into release/0.7.0 (8b1c9a3) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@                Coverage Diff                @@
##           release/0.7.0    #1905      +/-   ##
=================================================
+ Coverage          66.59%   66.62%   +0.03%     
=================================================
  Files                298      298              
  Lines               5245     5250       +5     
  Branches             945      949       +4     
=================================================
+ Hits                3493     3498       +5     
  Misses              1752     1752              

Files	Coverage Δ
services/blockchain-connector/config.js	100.00% <100.00%> (ø)
services/blockchain-indexer/config.js	100.00% <100.00%> (ø)

[nagdahimanshu]

LGTM 👍