Revert to using random UA in Reddit search engine

tests/unit/engines/test_reddit.py

@@ -3,7 +3,6 @@ import mock
 from searx.engines import reddit
 from searx.testing import SearxTestCase
 from datetime import datetime
-from searx.utils import searx_useragent
 
 
 class TestRedditEngine(SearxTestCase):
@@ -15,7 +14,6 @@ class TestRedditEngine(SearxTestCase):
         self.assertTrue('url' in params)
         self.assertTrue(query in params['url'])
         self.assertTrue('reddit.com' in params['url'])
-        self.assertEqual(params['headers']['User-Agent'], searx_useragent())
 
     def test_response(self):
         resp = mock.Mock(text='{}')