proxy needs to add weavewait to execs as well

Bug came up in a test where we are restarting and doing an exec checking
a network interface right away. weavewait is only added if the container
has a WEAVE_CIDR var set, the same as at container creation.

test/640_proxy_restart_reattaches_test.sh

@@ -14,7 +14,7 @@ docker_proxy_on $HOST1 run -e WEAVE_CIDR=$C2/24 -dt --name=c2 -h $NAME gliderlab
 docker_proxy_on $HOST1 run -e WEAVE_CIDR=$C1/24 -dt --name=c1 aanand/docker-dnsutils /bin/sh
 
 docker_proxy_on $HOST1 restart c2
-assert_raises "exec_on $HOST1 c2 ip link show ethwe | grep 'state UP'"
+assert_raises "proxy_exec_on $HOST1 c2 ip link show ethwe | grep 'state \\(UP\\|UNKNOWN\\)'"
 assert_dns_record $HOST1 c1 $NAME $C2
 
 end_suite

test/config.sh

@@ -97,6 +97,14 @@ exec_on() {
     docker -H tcp://$host:2375 exec $container "$@"
 }
 
+proxy_exec_on() {
+    host=$1
+    container=$2
+    shift 2
+    docker -H tcp://$host:12375 exec $container "$@"
+}
+
+
 start_container() {
     host=$1
     shift 1