ox-html.el (org-html-link): Fix handling of abbreviated links which include a file: protocol

* ox-html.el (org-html-link): Fix handling of abbreviated
links which include a file: protocol.

Before the patch, exporting this buffer does not export the link correctly:

#+LINK: test file:my.file::%s

[[test::search]]

lisp/ox-html.el

@@ -2518,7 +2518,8 @@ INFO is a plist holding contextual information.  See
 			      (org-element-property :path link) option)))
 			(and numbers (concat "#sec-"
 					     (mapconcat 'number-to-string
-							numbers "-")))))))))
+							numbers "-"))))))
+		    (t raw-path))))
 	   (t raw-path)))
 	 attributes protocol)
     ;; Extract attributes from parent's paragraph. HACK: Only do this