local-addresses: call 'assert_not_reached' where appropriate (#31728)

Added code for calling the 'assert_not_reached' function as the value of the 'family' parameter must be either 'AF_INET' or 'AF_INET6'.

src/shared/local-addresses.c

@@ -211,7 +211,7 @@ int local_addresses(
                         break;
 
                 default:
-                        continue;
+                        assert_not_reached();
                 }
 
                 r = add_local_address(&list, &n_list, ifi, scope, family, &a);