update lua script to use new remote_id lookup API

scripts/s_chanmap.lua

@@ -16,7 +16,7 @@ function factory () return function ()
 		r:add_processor_by_index(proc, 0, nil, true)
 	end
 
-	r = Session:route_by_remote_id(1)
+	r = Session:get_remote_nth_route(1)
 	checksetup (r)
 	pi = r:nth_plugin(0):to_insert()
 

scripts/s_plugin_automation.lua

@@ -6,7 +6,7 @@ function factory () return function ()
 	local samplerate = Session:nominal_frame_rate ()
 
 	-- get Track/Bus with RID 3
-	local r = Session:route_by_remote_id(3)
+	local r = Session:get_remote_nth_route(3)
 	-- make sure the track object exists
 	assert (not r:isnil ())
 

scripts/s_pluginutils.lua

@@ -15,7 +15,7 @@ function factory () return function ()
 
 	-------------------------------------------------------------------------------
 	-- load a plugin preset
-	route = Session:route_by_remote_id(2)
+	route = Session:get_remote_nth_route(2)
 	-- to 4th plugin (from top), ardour starts counting at zero
 	plugin = route:nth_plugin(3):to_insert():plugin(0)
 	ps = plugin:preset_by_label("cutbass") -- get preset by name

scripts/s_replaceplugin.lua

@@ -2,7 +2,7 @@ ardour { ["type"] = "Snippet", name = "Replace Plugin" }
 
 function factory () return function ()
 
-	route = Session:route_by_remote_id(1)
+	route = Session:get_remote_nth_route(1)
 	old = route:nth_plugin(0)
 	new = ARDOUR.LuaAPI.new_plugin(Session, "http://gareus.org/oss/lv2/fil4#stereo", ARDOUR.PluginType.LV2, "");
 	route:replace_processor (old, new, nil)