Update PacketFilter.py

Author: lucadivit

PacketFilter.py

@@ -9,7 +9,7 @@ def __init__(self, ip_whitelist_filter=[], ip_blacklist_filter=[], IPv4=False, T
         self.UDP = UDP
         self.ICMP = ICMP
         filters = [self.IPv4, self.TCP, self.UDP, self.ICMP]
-        assert sum(filters) == 1, "You have to set one, and just one protocol filter."
+        assert sum(filters) <= 1, "You have to set just one protocol filter."
         if(len(self.ip_whitelist_filter) > 0 or len(self.ip_blacklist_filter) > 0):
             self.set_IPv4_filter(True)
 
@@ -117,4 +117,4 @@ def get_ip_whitelist_filter(self):
         return self.ip_whitelist_filter
 
     def get_ip_blacklist_filter(self):
-        return self.ip_blacklist_filter
+        return self.ip_blacklist_filter