libpng: update to 1.6.50

mingw-w64-libpng/PKGBUILD

@@ -3,7 +3,7 @@
 _realname=libpng
 pkgbase=mingw-w64-${_realname}
 pkgname="${MINGW_PACKAGE_PREFIX}-${_realname}"
-pkgver=1.6.49
+pkgver=1.6.50
 pkgrel=1
 arch=('any')
 mingw_arch=('mingw32' 'mingw64' 'ucrt64' 'clang64' 'clangarm64')
@@ -20,7 +20,7 @@ msys2_references=(
 )
 source=("https://downloads.sourceforge.net/sourceforge/libpng/${_realname}-${pkgver}.tar.xz"
         "libpng-${pkgver}-apng.patch::https://raw.githubusercontent.com/mozilla/gecko-dev/3f2c4cf90aa8c839a7d346022c6a77ad3713d486/media/libpng/apng.patch")
-sha256sums=('43182aa48e39d64b1ab4ec6b71ab3e910b67eed3a0fff3777cf8cf40d6ef7024'
+sha256sums=('4df396518620a7aa3651443e87d1b2862e4e88cad135a8b93423e01706232307'
             '4ebab105c07e819ad41101eb7a02d680d180b2534e04504ff4a583e02eb5da52')
 validpgpkeys=('8048643BA2C840F4F92A195FF54984BFA16C640F')  # Glenn Randers-Pehrson (mozilla) <glennrp+bmo@gmail.com>