Changes

ggsn: f_wait_icmp4: ignore ICMPv4 redirect

In the test TC_pdp4_clients_interact_with_txseq, the testsuite opens two
PDP contexts and sends a ping (ICMP echo request) from the first context
to the second, then waits with f_wait_icmp4 until the ping arrives at
the second PDP context.

When running the test with testenv and podman, an additional ICMP
redirect packet arrives, before the ICMP echo request arrives. The
redirect packet has the TEID of the first PDP context, and so
f_wait_icmp4 fails if we don't ignore this redirect packet.

Adjust f_wait_icmp4 to ignore such redirect packets.

Change-Id: I6dff4db1fb0803a02f412ff23bb5dcac8e50a504