env/windows: fix buglet in windows versions

Pick windows-server-2008-r2-dc-v20200114 for the 2008 version of
server-2008r2-v8 (the one we selected before doesn't exist).

Updates golang/go#35006

Change-Id: I02e5e4fb5085173f926af5caa45518f333ab5614
Reviewed-on: https://go-review.googlesource.com/c/build/+/410241
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
diff --git a/env/windows/make.bash b/env/windows/make.bash
index 707b888..2bc8c55 100755
--- a/env/windows/make.bash
+++ b/env/windows/make.bash
@@ -10,7 +10,7 @@
 
 public_images=(
          ['server-2016-v8']='windows-server-2016-dc-core-v20220513'
-         ['server-2008r2-v8']='windows-server-2008-r2-dc-v20220513'
+         ['server-2008r2-v8']='windows-server-2008-r2-dc-v20200114'
          ['server-2012r2-v8']='windows-server-2012-r2-dc-core-v20220513'
        )