Merge pull request #1150: Update Git to vfs-2.21.0

Updates Git to 2.21.0, as rebased in microsoft/git#122.

Author: derrickstolee

GVFS/GVFS.Build/GVFS.props

@@ -3,7 +3,7 @@
 
   <PropertyGroup Label="Parameters">
     <GVFSVersion>0.2.173.2</GVFSVersion>
-    <GitPackageVersion>2.20190312.1</GitPackageVersion>
+    <GitPackageVersion>2.20190522.3</GitPackageVersion>
   </PropertyGroup>
 
   <PropertyGroup Label="DefaultSettings">