luci-app-frpc: fix service status bar style

mod the service status bar to use normaly 'cbi-section' class style.

Signed-off-by: ZiMing Mo <msylgj@immortalwrt.org>
[squash commits, add balnk line between commit subject and message]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>