[appeveyor] rewrite mirrorlist (testing)

https://github.com/msys2/MINGW-packages/issues/7084#issuecomment-703211308

appveyor.yml

@@ -26,8 +26,10 @@ install:
 - c:\msys64\usr\bin\bash -lc "curl -O https://mirror.selfnet.de/msys2/msys/x86_64/msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz.sig"
 - c:\msys64\usr\bin\bash -lc "pacman-key --verify msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz.sig"
 - c:\msys64\usr\bin\bash -lc "pacman --noconfirm -U msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz"
-# disable inaccessible miror - https://github.com/msys2/MINGW-packages/issues/7084
-- c:\msys64\usr\bin\bash -lc "sed -e '/repo\.msys2\.org/ s/^#*/#/' -i /etc/pacman.d/mirrorlist.*"
+# disable inaccessible miror (something block sed from changing files, so rewrite them) - https://github.com/msys2/MINGW-packages/issues/7084
+- c:\msys64\usr\bin\bash -lc "echo 'Server = https://mirror.yandex.ru/mirrors/msys2/mingw/x86_64/' > /etc/pacman.d/mirrorlist.mingw64"
+- c:\msys64\usr\bin\bash -lc "echo 'Server = https://mirror.yandex.ru/mirrors/msys2/mingw/i686/' > /etc/pacman.d/mirrorlist.mingw32"
+- c:\msys64\usr\bin\bash -lc "echo 'Server = https://mirror.yandex.ru/mirrors/msys2/msys/$arch/' > /etc/pacman.d/mirrorlist.msys"
 - c:\msys64\usr\bin\bash -lc "cat /etc/pacman.d/mirrorlist.*"
 # remove packages which can break build
 - c:\msys64\usr\bin\bash -lc "pacman --noconfirm -Rns gcc-fortran gcc mingw-w64-{i686,x86_64}-gcc-ada mingw-w64-{i686,x86_64}-gcc-objc"