Disable Nanostack border router test

Pending Nanostack EMAC work, disable the border router.

Author: kjbracey

tools/test/examples/examples.json

@@ -222,8 +222,8 @@
       "targets" : ["K64F", "K66F", "NUCLEO_F429ZI"],
       "toolchains" : [],
       "exporters": [],
-      "compile" : true,
-      "export": true,
+      "compile" : false,
+      "export": false,
       "auto-update" : false
     },
     {