[plotters][views] Fix key search in dictionaries

beat/web/plotters/views.py

@@ -99,7 +99,7 @@ def plot(request):
 
     report_experiments = None
 
-    if use.has_key("report_number"):
+    if "report_number" in use:
         try:
             report = Report.objects.get(number = int(use["report_number"]))
         except: