eur-lex: make the background "antiquewhite" (a very light pink).

And why antiquewhite? Because firefox has shown it in the completion list.

eur-lex/eur-lex_toc.user.js

@@ -24,6 +24,7 @@ style.innerHTML = '\
 #the-toc-this-website-lacks > div {\
   direction: ltr;\
   overflow-x: auto;\
+  background-color: antiquewhite;\
 }\
 #the-toc-this-website-lacks li {\
   padding: 0.5em;\