bufix mixer-proxy log level flag, go fmt
bufix mixer-proxy log level flag, go fmt

fengshao0907/mixer,leohdr/mixer,flashbuckets/mixer,maxencoder/mixer,fengshao0907/mixer,shenli/mixer,deafgoat/mixer,siddontang/mixer,leohdr/mixer,flashbuckets/mixer,siddontang/mixer,maxencoder/mixer,shenli/mixer,deafgoat/mixer