Fix TypeError: 'list' object is not an iterator for test_cacl_applica…

…tion (sonic-net#9022)

What is the motivation for this PR?
test_cacl_application failed on dualtor testbed due to TypeError: 'list' object is not an iterator.
That's because the type of ip_ntwrk.hosts() is list for LOOPBACK_INTERFACE ip address FC00:1::38/128, can't be called for next() function.
For VLAN_INTERFACE, it has some non-ip address key for dualtor testbed, such as grat_arp or proxy_arp, if call ipaddress.ip_network for them, it will throw ValueError exception, but in existing code, it executes pass next. At this time, the iface_table_name == "VLAN_INTERFACE", the code will execute next() function for previous ip_ntwrk which is got from LOOPBACK_INTERFACE. According to previous saying, the TypeError: 'list' object is not an iterator will happen here.

Signed-off-by: Zhaohui Sun <zhaohuisun@microsoft.com>

tests/cacl/test_cacl_application.py

@@ -322,7 +322,7 @@ def generate_and_append_block_ip2me_traffic_rules(duthost, iptables_rules, ip6ta
                         # There are non-ip_address keys in ifaces. We ignore them with the except
                         ip_ntwrk = ipaddress.ip_network(iface_cidr, strict=False)
                     except ValueError:
-                        pass
+                        continue
                     # For VLAN interfaces, the IP address we want to block is the default gateway (i.e.,
                     # the first available host IP address of the VLAN subnet)
                     ip_addr = next(ip_ntwrk.hosts()) if iface_table_name == "VLAN_INTERFACE" \