Fix multiple connections in curl hook

[Yurunsoft]

I have problems downloading FTP files using curl because the FTP protocol creates two connections

[codecov[bot]]

Codecov Report

Merging #4826 (d704d89) into 4.8.x (e506f0b) will decrease coverage by 0.25%. The diff coverage is n/a.

@@            Coverage Diff             @@
##            4.8.x    #4826      +/-   ##
==========================================
- Coverage   52.73%   52.47%   -0.26%     
==========================================
  Files          73       73              
  Lines       14942    15187     +245     
==========================================
+ Hits         7879     7970      +91     
- Misses       7063     7217     +154     

Impacted Files	Coverage Δ
src/protocol/dtls.cc	76.85% <ø> (+3.70%)	:arrow_up:
src/server/static_handler.cc	25.98% <0.00%> (-10.26%)	:arrow_down:
src/os/unix_socket.cc	60.00% <0.00%> (-4.29%)	:arrow_down:
src/protocol/base.cc	62.65% <0.00%> (-1.81%)	:arrow_down:
src/wrapper/event.cc	87.27% <0.00%> (-1.62%)	:arrow_down:
src/os/pipe.cc	67.92% <0.00%> (-1.31%)	:arrow_down:
src/core/base.cc	69.24% <0.00%> (-1.19%)	:arrow_down:
src/network/stream.cc	87.17% <0.00%> (-1.14%)	:arrow_down:
src/protocol/redis.cc	58.99% <0.00%> (-1.01%)	:arrow_down:
src/reactor/epoll.cc	74.52% <0.00%> (-0.71%)	:arrow_down:
... and 28 more

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more