added missing coma in camera.py.template

backend/cameras.py.template

@@ -3,7 +3,7 @@ restaurants = [
         "restaurant": "local",
         # the linear function estimating the waiting time t based on the number of people n and the number c of open checkouts is:
         # t = a * n / c + b
-        "a_factor": 30 # slope
+        "a_factor": 30, # slope
         "b_factor": 120, # y-intercept
         # list of all the cameras that correspond to a same restaurant
         "cameras":