transport: Remove redundant if in handleGoAway

[narqo]

This PR fixes a typo in http2Client, removing the redundant checks in the handleGoAway

RELEASE NOTES: none

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: narqo / name: Vladimir Varankin (fe37859)

[codecov]

Codecov Report

Merging #6930 (fe37859) into master (987df13) will increase coverage by 0.06%.
Report is 1 commits behind head on master.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6930      +/-   ##
==========================================
+ Coverage   83.66%   83.72%   +0.06%     
==========================================
  Files         287      287              
  Lines       30931    30930       -1     
==========================================
+ Hits        25879    25897      +18     
+ Misses       3987     3972      -15     
+ Partials     1065     1061       -4     

Files	Coverage Δ
internal/transport/http2_client.go	90.76% <100.00%> (-0.09%)	⬇️

... and 14 files with indirect coverage changes