Update downloader-middleware.rst

[PendalF89]

Added a link to the method

[codecov]

Codecov Report

Merging #5419 (95c1465) into master (5d7c0a5) will decrease coverage by 4.32%.
The diff coverage is n/a.

❗ Current head 95c1465 differs from pull request most recent head bbb693d. Consider uploading reports for the commit bbb693d to get more accurate results

@@            Coverage Diff             @@
##           master    #5419      +/-   ##
==========================================
- Coverage   88.77%   84.45%   -4.33%     
==========================================
  Files         163      163              
  Lines       10641    10641              
  Branches     1813     1813              
==========================================
- Hits         9447     8987     -460     
- Misses        919     1391     +472     
+ Partials      275      263      -12     

Impacted Files	Coverage Δ
scrapy/utils/asyncgen.py	33.33% <0.00%> (-66.67%)	⬇️
scrapy/core/http2/stream.py	27.01% <0.00%> (-64.37%)	⬇️
scrapy/pipelines/images.py	27.82% <0.00%> (-62.61%)	⬇️
scrapy/core/http2/agent.py	36.14% <0.00%> (-60.25%)	⬇️
scrapy/core/downloader/handlers/http2.py	43.42% <0.00%> (-56.58%)	⬇️
scrapy/core/http2/protocol.py	34.17% <0.00%> (-49.25%)	⬇️
scrapy/robotstxt.py	75.30% <0.00%> (-22.23%)	⬇️
scrapy/utils/test.py	43.75% <0.00%> (-17.19%)	⬇️
scrapy/utils/ssl.py	53.65% <0.00%> (-17.08%)	⬇️
scrapy/utils/spider.py	69.69% <0.00%> (-12.13%)	⬇️
... and 8 more