fix: avoid connection when web socket server is not running

[alexander-akait]

• This is a bugfix
• This is a feature
• This is a code refactor
• This is a test update
• This is a docs update
• This is a metadata update

For Bugs and Features; did you add new tests?

yes

Motivation / Use-Case

fixes #3873

Breaking Changes

No

Additional Info

no

[codecov]

Codecov Report

Merging #3879 (5bf73e0) into master (01b178d) will decrease coverage by 0.08%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3879      +/-   ##
==========================================
- Coverage   92.72%   92.63%   -0.09%     
==========================================
  Files          14       14              
  Lines        1334     1345      +11     
  Branches      467      468       +1     
==========================================
+ Hits         1237     1246       +9     
- Misses         89       92       +3     
+ Partials        8        7       -1     

Impacted Files	Coverage Δ
lib/Server.js	93.60% <100.00%> (-0.05%)	⬇️
client-src/index.js	80.76% <0.00%> (-0.61%)	⬇️

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