fix stack build on windows

For whatever reason, putting Win32-2.13.4.0 in stack.yaml results in
stack blowing up with many unrelated dependency problems.
But making git-annex depend on that version lets stack resolve deps.

git-annex.cabal

@@ -413,7 +413,7 @@ Executable git-annex
 
   if (os(windows))
     Build-Depends:
-      Win32 ((>= 2.6.1.0 && < 2.12.0.0) || >= 2.13.4.0),
+      Win32 (>= 2.13.4.0),
       setenv,
       process (>= 1.6.2.0),
       silently (>= 1.2.5.1)

stack.yaml

@@ -18,7 +18,6 @@ extra-deps:
 - torrent-10000.1.1
 - bencode-0.6.1.1
 - feed-1.3.2.1
-- Win32-2.13.4.0
 - git: https://github.com/sjakobi/bloomfilter.git
   commit: fb79b39c44404fd791a3bed973e9d844fb084f1e
 allow-newer: true