Messy fix for adobe#5262

The dialog can be dismissed, but it's not as nice as it should.
But it does it's job because you can't do anything else than typing in the input field after clicking a navigator button.

src/search/FindReplace.js

@@ -343,6 +343,7 @@ define(function (require, exports, module) {
             } else if (e.target.id === "find-prev") {
                 doSearch(editor, true);
             }
+            $(getDialogTextField()).focus();
         });
 
         var $input = getDialogTextField();