ripd: no need to use qobj anymore to keep track of "router rip"

ripd: no need to use qobj anymore to keep track of "router rip"

Now that "router rip" and all underlying commands were converted to the
new northbound model, there's no need to use the qobj infrastructure to
keep track of the 'rip' global variable anymore.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>