Dont skip host header

[noelzubin]

Closes #1740

[codecov-io]

Codecov Report

Merging #1744 (47dd1af) into master (40979fd) will decrease coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1744      +/-   ##
==========================================
- Coverage   71.40%   71.35%   -0.05%     
==========================================
  Files         178      178              
  Lines       13751    13749       -2     
==========================================
- Hits         9819     9811       -8     
- Misses       3320     3326       +6     
  Partials      612      612              

Flag	Coverage Δ
ubuntu	71.33% <100.00%> (-0.02%)	⬇️
windows	69.93% <50.00%> (-0.04%)	⬇️

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Impacted Files	Coverage Δ
js/modules/k6/http/request.go	80.50% <100.00%> (-0.14%)	⬇️
core/engine.go	90.95% <0.00%> (-2.02%)	⬇️
js/runner.go	80.45% <0.00%> (-0.66%)	⬇️

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[na--]

Thanks for making this PR, @noelzubin. Can you please also add some tests? Specifically:

• that the host header is accessible from response.request.headers (the problem exposed in Http response.request.headers are missing "host" value  #1740)
• how k6 will handle situations in which the host header is different from the URL that is being accessed
• (optional) how this interacts with the global k6 option hosts