The "network-clock-participate" command is used to allow the ports on a specified network module or voice/WAN interface card (VWIC) to use the network clock for timing. To restrict the device to use only its own clock signals,use the no form of this command. It appears that on your IOS version, the "no network-clock-participate" is on by default. If your WIC interface does not use any network clock for timing ("does not support clock participate"), the message can be ignored.
You will find the details of the clocking commands in the link below:
