lisp/ox-html.el: Minimal encoding for code and verbatim text

* lisp/ox-html.el: Remove fancy string replacements for code and
verbatim text when exporting to html.

Exporting =--option= or ~--option~ to html used to replace -- with a
ndash.

TINYCHANGE

lisp/ox-html.el

@@ -1988,7 +1988,7 @@ channel."
 CONTENTS is nil.  INFO is a plist holding contextual
 information."
   (format (or (cdr (assq 'code org-html-text-markup-alist)) "%s")
-	  (org-html-plain-text (org-element-property :value code) info)))
+	  (org-html-encode-plain-text (org-element-property :value code))))
 
 ;;;; Drawer
 
@@ -3096,7 +3096,7 @@ holding contextual information."
 CONTENTS is nil.  INFO is a plist holding contextual
 information."
   (format (or (cdr (assq 'verbatim org-html-text-markup-alist)) "%s")
-	  (org-html-plain-text (org-element-property :value verbatim) info)))
+	  (org-html-encode-plain-text (org-element-property :value verbatim))))
 
 ;;;; Verse Block