bug(webhooks): add configurable request timeout for webhooks

- Handle unhandled connection error while sending webhooks

onadata/apps/restservice/services/generic_json.py

@@ -4,10 +4,15 @@
 """
 import json
 
+from django.conf import settings
+
 import requests
+from requests.exceptions import ConnectionError
 
 from onadata.apps.restservice.RestServiceInterface import RestServiceInterface
 
+WEBHOOK_TIMEOUT = getattr(settings, "WEBHOOK_TIMEOUT", 30)
+
 
 class ServiceDefinition(RestServiceInterface):
     """Post submisison JSON data to an external service that accepts a JSON post."""
@@ -21,4 +26,9 @@ def send(self, url, data=None):
         if data:
             post_data = json.dumps(data.json)
             headers = {"Content-Type": "application/json"}
-            requests.post(url, headers=headers, data=post_data)
+            try:
+                requests.post(
+                    url, headers=headers, data=post_data, timeout=WEBHOOK_TIMEOUT
+                )
+            except ConnectionError:
+                pass