[SCB-322] merge config center modification#542

Merged

wujimin merged 2 commits intoapache:masterfrom

yhs0092:merge_config_center_client_modification

Feb 1, 2018

Commits on Jan 31, 2018

[SCB-322] merge config center modification
yaohaishi
committed

Commits on Feb 1, 2018

[SCB-322] use empty string as default PROXY_USER and PROXY_PASSWD
yaohaishi
committed