Fix empty raw responses parsed as json

[fmauNeko]

What does this PR do ?

Prevent passing empty strings into JSON.parse when using raw responses over HTTP.

[codecov]

Codecov Report

Merging #731 (feae1d1) into 7-dev (2257670) will decrease coverage by 0.18%.
Report is 14 commits behind head on 7-dev.
The diff coverage is 44.44%.

❗ Current head feae1d1 differs from pull request most recent head 2d99ca6. Consider uploading reports for the commit 2d99ca6 to get more accurate results

@@            Coverage Diff             @@
##            7-dev     #731      +/-   ##
==========================================
- Coverage   83.04%   82.86%   -0.18%     
==========================================
  Files          46       46              
  Lines        2112     2119       +7     
  Branches      408      410       +2     
==========================================
+ Hits         1754     1756       +2     
- Misses        279      282       +3     
- Partials       79       81       +2     

Files	Coverage Δ
src/protocols/Http.ts	82.44% <44.44%> (-2.09%)	⬇️