test(e2e): Add missing proxy listener to config file (#3715)

enos/modules/docker_boundary/boundary-config-bsr.hcl

@@ -33,6 +33,12 @@ listener "tcp" {
   tls_disable = true
 }
 
+listener "tcp" {
+  address     = "boundary:9202"
+  purpose     = "proxy"
+  tls_disable = true
+}
+
 listener "tcp" {
   address     = "boundary:9203"
   purpose     = "ops"