SPARK-1125: When using a http  proxy,the maven build error  for Spark Examples 

building with maven  When using a http  proxy, throw Failure to find org.eclipse.paho:mqtt-client:jar:0.4.0 in https://repository.apache.org/content/repositories/releases was cached in the local repository, resolution will not be reattempted until the update interval of apache-repo has elapsed or updates are forced