[fix] do not show DDG IP from zero click

The zero click result from DuckDuckGo for IP should not be displayed.  It will
return the IP of the searxng server, not the user's IP, and looks a bit strange
when the `self_info` plugin is enabled as two different IPs get returned.

searx/engines/duckduckgo.py

@@ -331,7 +331,7 @@ def response(resp):
     zero_click_info_xpath = '//html/body/form/div/table[2]/tr[2]/td/text()'
     zero_click = extract_text(eval_xpath(doc, zero_click_info_xpath)).strip()
 
-    if zero_click:
+    if zero_click and "Your IP address is" not in zero_click:
         current_query = resp.search_params["data"].get("q")
 
         results.append(