Drop Python 2 (1/n): remove unicode string and url_utils

searx/engines/stackoverflow.py

@@ -10,9 +10,9 @@
  @parse       url, title, content
 """
 
+from urllib.parse import urlencode, urljoin
 from lxml import html
 from searx.engines.xpath import extract_text
-from searx.url_utils import urlencode, urljoin
 
 # engine dependent config
 categories = ['it']