contrib: gnutls: replace the win32 patch with sed commands

It's more flexible after updates.
13 jobs for !13 with winrt/10 in 55 minutes and 51 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Build
passed #395770
amd64 docker
android-arm

00:12:46

passed #395771
amd64 docker
android-arm64

00:12:58

passed #395772
amd64 docker
android-x86

00:15:29

passed #395773
amd64 docker
android-x86_64

00:12:43

passed #395764
amd64 docker
debian

00:14:04

passed #395768
macos
ios-arm64

00:52:36

passed #395769
macos
ios-armv7

00:39:12

passed #395767
macos
macos

00:52:18

passed #395766
amd64 docker
raspbian-arm

00:10:07

passed #395765
amd64 docker
snap

00:27:59

passed #395761
amd64 docker
win32

00:40:21

passed #395762
amd64 docker
win64

00:28:28

passed #395763
amd64 docker
win64-llvm

00:28:05