Strip out some leading whitespace when looking at logs

* lisp/vc/vc-git.el (vc-git-expanded-log-entry): When looking
at expanded git logs with `vc-print-root-log' (C-x v L, then
<enter> by default), Emacs was stripping out all leading
whitespace from git logs.  I now strip exactly 2 leading
spaces, which retains the indentation in the logs (bug#18110).

lisp/vc/vc-git.el

@@ -970,7 +970,9 @@ or BRANCH^ (where \"^\" can be repeated)."
     (goto-char (point-min))
     (unless (eobp)
       ;; Indent the expanded log entry.
-      (indent-region (point-min) (point-max) 2)
+      (while (re-search-forward "^  " nil t)
+        (replace-match "")
+        (forward-line))
       (buffer-string))))
 
 (defun vc-git-region-history (file buffer lfrom lto)