Fix website dash replacement rust-lang#12718

Searching for a lint on the website will replace all of the dashes with
underscores instead of only the first one.

Author: roddyrap

util/gh-pages/script.js

@@ -406,7 +406,7 @@
                 }
 
                 // Search by id
-                if (lint.id.indexOf(searchStr.replace("-", "_")) !== -1) {
+                if (lint.id.indexOf(searchStr.replaceAll("-", "_")) !== -1) {
                     return true;
                 }