wait longer for ethwe interface to come up

in case we are running on a really, really slow machine/VM

weavedns/Dockerfile

@@ -3,4 +3,4 @@ MAINTAINER Weaveworks Inc <help@weave.works>
 WORKDIR /home/weave
 ADD ./weavedns /home/weave/
 EXPOSE 53/udp
-ENTRYPOINT ["/home/weave/weavedns", "-wait", "5"]
+ENTRYPOINT ["/home/weave/weavedns", "-wait", "20"]

weaver/Dockerfile

@@ -2,4 +2,4 @@ FROM scratch
 MAINTAINER Weaveworks Inc <help@weave.works>
 WORKDIR /home/weave
 ADD ./weaver /home/weave/
-ENTRYPOINT ["/home/weave/weaver", "-wait", "5"]
+ENTRYPOINT ["/home/weave/weaver", "-wait", "20"]