Fix test code OpeningHour.__str__() display

Author: vdboor

tests/test_gisserver/models.py

@@ -24,7 +24,7 @@ class OpeningHour(models.Model):
     end_time = models.TimeField(default=time(23, 30))
 
     def __str__(self):
-        return f"{self.get_weekday_display}: {self.start_time} - {self.end_time}"
+        return f"{self.get_weekday_display()}: {self.start_time} - {self.end_time}"
 
 
 class Restaurant(models.Model):