[connman] Add dccp to firewall protocols. Fix max port. JB#44071

Add dccp to supported protocols list. This is supported although
iptables manual page does not mention it.

Fix max port check to include also the max 16bit uint as accepted port
number.

connman/src/firewall.c

@@ -1261,6 +1261,7 @@ static bool is_string_digits(const char *str)
 						"ah",
 						"sctp",
 						"mh",
+						"dccp",
 						"all",
 						NULL
 	};
@@ -1468,7 +1469,7 @@ static bool validate_ports_or_services(const char *str)
 			portnum = (int) g_ascii_strtoll(tokens[i], NULL, 10);
 
 			/* Valid port number */
-			if (portnum && portnum < G_MAXUINT16)
+			if (portnum && portnum <= G_MAXUINT16)
 				continue;
 		}