[fix] gigablast url params

searx/engines/gigablast.py

 from urllib import urlencode
 from cgi import escape
 from lxml import etree
+from random import randint
+from time import time
 
 # engine dependent config
 categories = ['general']
 
 # search-url, invalid HTTPS certificate
 base_url = 'http://gigablast.com/'
-search_string = 'search?{query}&n={number_of_results}&s={offset}&xml=1&qh=0'
+search_string = 'search?{query}&n={number_of_results}&s={offset}&xml=1&qh=0&uxid={uxid}&rand={rand}'
 
 # specific xpath variables
 results_xpath = '//response//result'
     search_path = search_string.format(
         query=urlencode({'q': query}),
         offset=offset,
-        number_of_results=number_of_results)
+        number_of_results=number_of_results,
+        uxid=randint(10000, 10000000),
+        rand=int(time()))
 
     params['url'] = base_url + search_path