Infer number_of_agents from agent_list in apppointment booking settings

erpnext/crm/doctype/appointment_booking_settings/appointment_booking_settings.json

@@ -29,8 +29,10 @@
    "default": "1",
    "fieldname": "number_of_agents",
    "fieldtype": "Int",
+   "hidden": 1,
    "in_list_view": 1,
    "label": "Number of Concurrent Appointments",
+   "read_only": 1,
    "reqd": 1
   },
   {
@@ -99,7 +101,7 @@
   }
  ],
  "issingle": 1,
- "modified": "2019-11-19 10:53:26.935061",
+ "modified": "2019-11-20 10:23:37.393363",
  "modified_by": "Administrator",
  "module": "CRM",
  "name": "Appointment Booking Settings",

erpnext/crm/doctype/appointment_booking_settings/appointment_booking_settings.py

@@ -16,6 +16,12 @@ class AppointmentBookingSettings(Document):
 	def validate(self):
 		self.validate_availability_of_slots()
 
+	def save(self):
+		self.infer_number_of_agents()
+
+	def infer_number_of_agents():
+		self.number_of_agents = len(self.agent_list)
+
 	def validate_availability_of_slots(self):
 		for record in self.availability_of_slots:
 			from_time = datetime.datetime.strptime(