Autocomplete: don't suggest the current query.

Example of minor issue before this commit:
the autocompletion can suggest "Test" if the query is "Test".

searx/webapp.py

@@ -909,6 +909,7 @@ def autocompleter():
         for result in raw_results:
             # attention: this loop will change raw_text_query object and this is
             # the reason why the sug_prefix was stored before (see above)
+            if result != sug_prefix:
                 results.append(raw_text_query.changeQuery(result).getFullQuery())
 
     if len(raw_text_query.autocomplete_list) > 0: