Fix Windows version resources

Add FileVersion, which is a required field
As not all required fields were present, none were being included
Fixes git-for-windows#4090

Signed-off-by: Kiel Hurley <kielhurley@gmail.com>

Author: Mortein

git.rc.in

@@ -12,6 +12,7 @@ BEGIN
       VALUE "OriginalFilename", "git.exe\0"
       VALUE "ProductName", "Git\0"
       VALUE "ProductVersion", "@GIT_VERSION@\0"
+      VALUE "FileVersion", "@GIT_VERSION@\0"
     END
   END