Deploy git 2.18 to prod win depot_tools users.

R=hinoka

Bug: 851505
Change-Id: I355334c2a84f175452ff7c17f6b080d2815f0f4c
Reviewed-on: https://chromium-review.googlesource.com/1168131
Reviewed-by: Ryan Tseng <hinoka@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

bootstrap/win/manifest.txt

@@ -17,4 +17,4 @@ $VerifiedPlatform windows-386 windows-amd64
 infra/python/cpython/windows-386 version:2.7.6
 
 @Subdir git
-infra/git/windows-${arch} version:2.17.1.chromium15
+infra/git/windows-${arch} version:2.18.0.chromium16