Update docs for server_name in <tls_config>
Update docs for server_name in <tls_config>

chosenken/docs,open-falcon/open-falcon.github.io,du2016/prometheus-docs,open-falcon/open-falcon.github.io,Cepave/openfalcon.io,Cepave/openfalcon.io,prometheus/docs,chosenken/docs,tcolgate/docs,ddfreyne/prometheus-docs,du2016/prometheus-docs,open-falcon/open-falcon.github.io,tcolgate/docs,tcolgate/docs,ddfreyne/prometheus-docs,ddfreyne/prometheus-docs,ddfreyne/prometheus-docs,prometheus/docs,chosenken/docs,prometheus/docs,chosenken/docs,Cepave/openfalcon.io,du2016/prometheus-docs