modify the dockerfile to make sure it was built successfully

Dockerfile

@@ -3,11 +3,11 @@ FROM progrium/busybox
 WORKDIR /opt/weed
 
 RUN opkg-install curl
-RUN echo insecure >> ~/.curlrc
+RUN echo tlsv1 >> ~/.curlrc
 
 RUN \
   curl -Lks https://bintray.com$(curl -Lk http://bintray.com/chrislusf/seaweedfs/seaweedfs/_latestVersion | grep linux_amd64.tar.gz | sed -n "/href/ s/.*href=['\"]\([^'\"]*\)['\"].*/\1/gp") | gunzip | tar -xf - -C /opt/weed/ && \
-    mv weed_*/* /bin && \
+  mkdir ./bin &&  mv weed_*/* ./bin && \
   chmod +x ./bin/weed
 
 EXPOSE 8080