Doc: fixed wrong description of PBKEYLEN conflict resolution

[ethouris]

Fixes #2496

[codecov-commenter]

Codecov Report

Merging #2513 (e095d5f) into master (53735e1) will decrease coverage by 0.20%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2513      +/-   ##
==========================================
- Coverage   65.48%   65.28%   -0.21%     
==========================================
  Files          99      100       +1     
  Lines       19698    19767      +69     
==========================================
+ Hits        12900    12904       +4     
- Misses       6798     6863      +65     

Impacted Files	Coverage Δ
srtcore/packet.cpp	44.04% <0.00%> (-8.43%)	⬇️
srtcore/group.cpp	29.37% <0.00%> (-8.27%)	⬇️
srtcore/utilities.h	59.85% <0.00%> (-4.23%)	⬇️
test/test_bonding.cpp	94.21% <0.00%> (-4.22%)	⬇️
srtcore/group.h	59.18% <0.00%> (-2.05%)	⬇️
srtcore/window.cpp	81.81% <0.00%> (-1.30%)	⬇️
srtcore/netinet_any.h	88.77% <0.00%> (-1.03%)	⬇️
srtcore/buffer_rcv.cpp	58.83% <0.00%> (-0.20%)	⬇️
srtcore/core.h	72.15% <0.00%> (ø)
srtcore/queue.h	82.35% <0.00%> (ø)
... and 8 more

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[stevomatthews]

Minor edits.