Update client-send-message.lua to not do an initial sync

The initial sync is not needed, provided that the user has to supply anyway
the room ID or alias in the command line of the script.

examples/client-send-message.lua

@@ -12,13 +12,11 @@ if #arg ~= 4 then
 end
 
 local client = require "matrix" .client(arg[1])
-client:login_with_password(arg[2], arg[3])
 
--- FIXME: This does not resolve room aliases, it works only with room IDs
-local room = client.rooms[arg[4]]
-if not room then
-   room = client:join_room(arg[4])
-end
+-- Passing "true" as last parameter skips the initial sync, which can be slow
+client:login_with_password(arg[2], arg[3], true)
 
+local room = client:join_room(arg[4])
 room:send_text(io.read("*a"))
+
 client:logout()