tests: zebra_netlink only gives 10 seconds to install all routes

tests: zebra_netlink only gives 10 seconds to install all routes

Under really heavily loaded systems this is insufficient.  Looking
at the run output we have this:

	  "2.1.3.22\/32":[
	    {
	      "installed":true,
	    }
	  ],
	  "2.1.3.23\/32":[
	    {
	      "queued":true,
            }
           ],

So after 10 seconds on the micronet system only 30 of the 100 routes are installed.
Give it more time.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>