Update CentOS repo management docs link
Update CentOS repo management docs link

Closes-Bug: #1455661

Change-Id: Ie397a3d228996f109f39b0b646848cccb73b708d

prmtl/fuel-web,prmtl/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,stackforge/fuel-web,eayunstack/fuel-web,nebril/fuel-web,eayunstack/fuel-web,stackforge/fuel-web,huntxu/fuel-web,nebril/fuel-web,nebril/fuel-web,huntxu/fuel-web,prmtl/fuel-web,prmtl/fuel-web,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,nebril/fuel-web,stackforge/fuel-web,prmtl/fuel-web,nebril/fuel-web,huntxu/fuel-web,eayunstack/fuel-web,SmartInfrastructures/fuel-web-dev,SmartInfrastructures/fuel-web-dev,SmartInfrastructures/fuel-web-dev,eayunstack/fuel-web,eayunstack/fuel-web