[AppVeyor] make curl support redirect

appveyor.yml

@@ -26,10 +26,10 @@ install:
     - '%CYG_ROOT%/bin/bash -lc "echo initialize"'
     - choco install curl
     # Install ocaml
-    - curl -fsS -o cygwin-setup.exe --retry 3 https://cygwin.com/setup-x86.exe
+    - curl -fsSL -o cygwin-setup.exe --retry 3 https://cygwin.com/setup-x86.exe
     - 'cygwin-setup.exe -g -q -R "%CYG_ROOT%" -P make -P git -P mingw64-i686-zlib -P rsync -P patch -P diffutils -P curl -P unzip -P m4 -P perl -P mingw64-i686-gcc-core -P mingw64-i686-pcre'
     - if not exist "opam32.tar.xz" (
-        curl -fsS -o opam32.tar.xz --retry 3 https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.1/opam32.tar.xz
+        curl -fsSL -o opam32.tar.xz --retry 3 https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.1/opam32.tar.xz
       )
     - 7z x "opam32.tar.xz" -so | 7z x -aoa -si -ttar
     - '%CYG_ROOT%/bin/bash -lc "cd \"$OLDPWD\" && bash opam32/install.sh"'