Fix alert occurrence query formatting

- not properly handled "=" signs

Change-Id: I891ab4cb4fde2d42b04579817c00937a14c66c0c
Related-PROD: PRODX-7212
diff --git a/sf_notifier/helpers.py b/sf_notifier/helpers.py
index 1c99a0a..b425de4 100644
--- a/sf_notifier/helpers.py
+++ b/sf_notifier/helpers.py
@@ -14,7 +14,6 @@
 #    under the License.
 
 import os
-import urllib
 
 RESOLVED_STATUSES = ('UP', 'OK', 'resolved')
 
@@ -46,14 +45,13 @@
     # switch from Console to Graph tab to show trends
     condition_url = alert['generatorURL'].replace('g0.tab=1', 'g0.tab=0')
 
-    # list alert instances in the cluster
-    # because of Python formatting - double braces were used
+    # list alert firing instances in the cluster
+    # via query: ALERTS{alertname="<alertname>",alertstate="firing"}
     alert_query = ('g1.range_input=1h&'
-                   'g1.expr=ALERTS{{alertname="{alertname}",'
-                   'alertstate="firing"}}&'
-                   'g1.tab=0')
-    alert_query = alert_query.format(**alert['labels'])
-    alert_query = urllib.quote(alert_query)
+                   'g1.expr=ALERTS%7Balertname%3D%22'
+                   '{}'
+                   '%22%2Calertstate%3D%22firing%22%7D&'
+                   'g1.tab=0').format(alert['labels']['alertname'])
     return '{}&{}'.format(condition_url, alert_query)