Fix Reference tests which copy the git directory

Delphi 2007 was failing to copy the git directory with
ShellAPI.ShFileOperation(), while D2009 was not failing probably because
it uses the WideChar version of the WINAPI function.

Author: jasonpenny

TestsFromLibGit2/uTestsFromLibGit2.pas

@@ -232,8 +232,8 @@ function TTestFromLibGit2.copydir_recurs(const fromDir, toDir: string): Boolean;
 
   fos.wFunc  := FO_COPY;
   fos.fFlags := FOF_FILESONLY;
-  fos.pFrom  := PChar(fromDir);
-  fos.pTo    := PChar(toDir);
+  fos.pFrom  := PChar(fromDir + #0);
+  fos.pTo    := PChar(toDir + #0);
 
   Result := (0 = ShellAPI.ShFileOperation(fos));
 end;