Bugfix search function xlt-documentation

[kqmpetenz]

Found via TA. If you type something into the search bar and press "ENTER" before the suggestion-window is loaded properly, expected results will not be displayed at all. Instead it just adds the query-string to the URL and an empty results-page is displayed.

Steps to reproduce:

• Go to the xlt documentation page
• Click the search bar and fastly type an input string
• Press enter before the suggestion window is visible

Expected behavior:

• Load and display the first result of the suggestion window

Actual behavior:

• The query string is added to the URL
• No results are displayed at all