network/dhclient.conf: add missing commata

options need to be seperated by ,

modules.d/40network/dhclient.conf

@@ -3,4 +3,4 @@ option classless-routes code 121 = array of unsigned integer 8;
 
 request subnet-mask, broadcast-address, time-offset, routers,
         domain-name, domain-name-servers, domain-search, host-name,
-        root-path, interface-mtu classless-routes;
+        root-path, interface-mtu, classless-routes;