site.conf: mesh.batman_adv.routing_algo is necessary in minimal setup

contrib/ci/minimal-site/site.conf

@@ -85,16 +85,11 @@
     ip6 = 'fd::1',
   },
 
-  -- Options specific to routing protocols (optional)
-  -- mesh = {
-    -- Options specific to the batman-adv routing protocol (optional)
-    -- batman_adv = {
-      -- Gateway selection class (optional)
-      -- The default class 20 is based on the link quality (TQ) only,
-      -- class 1 is calculated from both the TQ and the announced bandwidth
-      -- gw_sel_class = 1,
-    -- },
-  -- },
+  mesh = {
+    batman_adv = {
+      routing_algo = 'BATMAN_IV'
+    }
+  },
 
   mesh_vpn = {
     -- enabled = true,