Hello,
No, you do not need a license for the content filter. Actually, Cisco does not have a license for this device.
Content Filter is available under the Firewall tab in the management of the device. The filter, however, will only block HTTP traffic.
Admin guide below, Page 110
http://www.cisco.com/c/dam/en/us/td/docs/routers/csbr/rv0xx/administration/guide/rv0xx_AG_78-19576.pdf
Best Regards,
Mike