fix int overflow when parsing the transport parameters

[marten-seemann]

No description provided.

[codecov-commenter]

Codecov Report

Merging #2564 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2564   +/-   ##
=======================================
  Coverage   86.17%   86.17%           
=======================================
  Files         122      122           
  Lines        9550     9550           
=======================================
  Hits         8229     8229           
  Misses        983      983           
  Partials      338      338           

Impacted Files	Coverage Δ
internal/wire/transport_parameters.go	89.38% <100.00%> (ø)

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