rabbitmq_peer_discovery_consul: Set bind_addr to 127.0.0.1 in test config

[Why]
The test configuration was querying a network interface IP address based
on its name. However, the name, "eth0", is very specific to Linux. This
broke the test on other systems.

[How]
We still have to set an explicit `bind_addr` because Consul refuses to
start if the host has multiple private IPv4 addresses, as it is the case
in CI.

Therefore, we hard-code 127.0.0.1 as the IPv4 address to use because it has a
great chance to exist about anywhere.

Author: dumbbell

deps/rabbitmq_peer_discovery_consul/test/system_SUITE_data/consul.hcl

@@ -23,7 +23,7 @@ connect {
 
 # Addresses and ports
 client_addr = "0.0.0.0"
-bind_addr = "{{ GetInterfaceIP \"eth0\" }}"
+bind_addr = "127.0.0.1"
 
 addresses {
   grpc = "0.0.0.0"