gluon-core: remove more obsolete migrations

package/gluon-core/luasrc/lib/gluon/upgrade/210-interface-wan

@@ -22,8 +22,4 @@ if uci:get('network', 'mesh_wan', 'transitive') == nil then
 	uci:set('network', 'mesh_wan', 'transitive', true)
 end
 
-uci:delete('network', 'mesh_wan', 'auto')
-uci:delete('network', 'mesh_wan', 'fixed_mtu')
-uci:delete('network', 'mesh_wan', 'legacy')
-
 uci:save('network')

package/gluon-core/luasrc/lib/gluon/upgrade/220-interface-lan

@@ -50,8 +50,4 @@ if uci:get('network', 'mesh_lan', 'transitive') == nil then
 	uci:set('network', 'mesh_lan', 'transitive', true)
 end
 
-uci:delete('network', 'mesh_lan', 'auto')
-uci:delete('network', 'mesh_lan', 'fixed_mtu')
-uci:delete('network', 'mesh_lan', 'legacy')
-
 uci:save('network')