docs/wired make uci commit more specific (#942)

propose to make uci commit more specific to minimize unwanted changes in other temporary written config files like wireless ssid (in some offline changers)

docs/features/wired-mesh.rst

@@ -33,12 +33,12 @@ Mesh-on-WAN
 It's possible to enable Mesh-on-WAN like this::
 
   uci set network.mesh_wan.auto=1
-  uci commit
+  uci commit network
 
 It may be disabled by running::
 
   uci set network.mesh_wan.auto=0
-  uci commit
+  uci commit network
 
 
 Mesh-on-LAN
@@ -50,7 +50,7 @@ Configuring Mesh-on-LAN is a bit more complicated::
   for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
     uci del_list network.client.ifname=$ifname
   done
-  uci commit
+  uci commit network
 
 It may be disabled by running::
 
@@ -58,7 +58,7 @@ It may be disabled by running::
   for ifname in $(cat /lib/gluon/core/sysconfig/lan_ifname); do
     uci add_list network.client.ifname=$ifname
   done
-  uci commit
+  uci commit network
 
 Please note that this configuration has changed in Gluon v2016.1. Using
 the old commands on v2016.1 and later will break the corresponding options