typeahead: Use text() instead of html() in set_value.

This particular codepath is never reached right now,
because set_value is only called when `naturalSearch`
is `true`, and the only instance of `naturalSearch`
isn't for a `contenteditable` field.

But we don't need to use `html()` here because it's
displaying a plain string typeahead option.

web/third/bootstrap-typeahead/typeahead.js

@@ -207,7 +207,7 @@ Typeahead.prototype = {
     set_value() {
         const val = this.$menu.find(".active").data("typeahead-value");
         if (this.$element.is("[contenteditable]")) {
-            this.$element.html(val);
+            this.$element.text(val);
         } else {
             this.$element.val(val);
         }