Fix entity definition of \nbsp

* lisp/org-entities.el (org-entities): Use a proper non-breaking space
for \nbsp.

lisp/org-entities.el

@@ -281,7 +281,7 @@ packages to be loaded, add these packages to `org-latex-packages-alist'."
      ("ddag" "\\ddag{}" nil "‡" "[doubledagger]" "[doubledagger]" "‡")
 
      "** Whitespace"
-     ("nbsp" "~" nil " " " " " " " ")
+     ("nbsp" "~" nil " " " " "\x00A0" "\x00A0")
      ("ensp" "\\hspace*{.5em}" nil " " " " " " " ")
      ("emsp" "\\hspace*{1em}" nil " " " " " " " ")
      ("thinsp" "\\hspace*{.2em}" nil " " " " " " " ")