Fix TCP high-water release note

Add missing GitLab issue number to the TCP high-water release note.
66 jobs for !2541 with 1206-fix-tcp-high-water-release-note in 11 seconds (queued for 10 seconds)
latest detached
Status Job ID Name Coverage
  Precheck
canceled #400891
amd64 linux
🐞:sid:amd64

00:00:08

canceled #400889
amd64 linux
autoreconf:sid:amd64

00:00:11

canceled #400890
amd64 linux
misc:sid:amd64

00:00:08

 
  Build
canceled #400904
amd64 linux
asan:sid:amd64

canceled #400910
amd64 freebsd
clang:freebsd11.3:amd64

canceled #400911
amd64 freebsd
clang:freebsd12.0:amd64

canceled #400912
amd64 openbsd
clang:openbsd6.5:amd64

canceled #400907
amd64 linux
clang:stretch:amd64

canceled #400908
i386 linux
clang:stretch:i386

canceled #400892
amd64 linux
gcc:alpine3.10:amd64

canceled #400903
amd64 linux
gcc:bionic:amd64

canceled #400898
amd64 linux
gcc:buster:amd64

canceled #400893
amd64 linux
gcc:centos6:amd64

canceled #400894
amd64 linux
gcc:centos7:amd64

canceled #400895
amd64 linux
gcc:centos8:amd64

canceled #400901
amd64 linux
gcc:fedora30:amd64

canceled #400896
amd64 linux
gcc:jessie:amd64

canceled #400899
amd64 linux
gcc:sid:amd64

canceled #400900
i386 linux
gcc:sid:i386

canceled #400897
amd64 linux
gcc:stretch:amd64

canceled #400902
amd64 linux
gcc:xenial:amd64

canceled #400914
amd64 windows
msvc:windows:amd64

canceled #400906
amd64 linux
mutexatomics:sid:amd64

canceled #400913
amd64 linux
nolibtool:sid:amd64

canceled #400909
amd64 linux
pkcs11:sid:amd64

canceled #400905
amd64 linux
rwlock:sid:amd64

 
  Unit
canceled #400927
amd64 linux
unit:asan:sid:amd64

canceled #400931
amd64 freebsd
unit:clang:freebsd11.3:amd64

canceled #400932
amd64 freebsd
unit:clang:freebsd12.0:amd64

canceled #400929
amd64 linux
unit:clang:stretch:amd64

canceled #400915
amd64 linux
unit:gcc:alpine3.10:amd64

canceled #400926
amd64 linux
unit:gcc:bionic:amd64

canceled #400921
amd64 linux
unit:gcc:buster:amd64

canceled #400916
amd64 linux
unit:gcc:centos6:amd64

canceled #400917
amd64 linux
unit:gcc:centos7:amd64

canceled #400918
amd64 linux
unit:gcc:centos8:amd64

canceled #400924
amd64 linux
unit:gcc:fedora30:amd64

canceled #400919
amd64 linux
unit:gcc:jessie:amd64

canceled #400922
amd64 linux
unit:gcc:sid:amd64

canceled #400923
i386 linux
unit:gcc:sid:i386

canceled #400920
amd64 linux
unit:gcc:stretch:amd64

canceled #400925
amd64 linux
unit:gcc:xenial:amd64

canceled #400933
amd64 linux
unit:nolibtool:sid:amd64

canceled #400930
amd64 linux
unit:pkcs11:sid:amd64

canceled #400928
amd64 linux
unit:rwlock:sid:amd64

 
  System
canceled #400946
amd64 linux
system:asan:sid:amd64

canceled #400949
amd64 freebsd
system:clang:freebsd11.3:amd64

canceled #400950
amd64 freebsd
system:clang:freebsd12.0:amd64

canceled #400934
amd64 linux
system:gcc:alpine3.10:amd64

canceled #400945
amd64 linux
system:gcc:bionic:amd64

canceled #400940
amd64 linux
system:gcc:buster:amd64

canceled #400935
amd64 linux
system:gcc:centos6:amd64

canceled #400936
amd64 linux
system:gcc:centos7:amd64

canceled #400937
amd64 linux
system:gcc:centos8:amd64

canceled #400943
amd64 linux
system:gcc:fedora30:amd64

canceled #400938
amd64 linux
system:gcc:jessie:amd64

canceled #400941
amd64 linux
system:gcc:sid:amd64

canceled #400942
i386 linux
system:gcc:sid:i386

canceled #400939
amd64 linux
system:gcc:stretch:amd64

canceled #400944
amd64 linux
system:gcc:xenial:amd64

canceled #400951
amd64 linux
system:nolibtool:sid:amd64

canceled #400948
amd64 linux
system:pkcs11:sid:amd64

canceled #400947
amd64 linux
system:rwlock:sid:amd64

 
  Docs
canceled #400952
amd64 linux
docs:sid:amd64

 
  Postcheck
canceled #400954
amd64 linux
cppcheck:gcc:sid:amd64

canceled #400953
amd64 linux
scan-build:buster:amd64