Reduce one step to message via WhatsApp web

[gitcommitshow]

So on desktop, people can use either "WhatsApp desktop client" or "WhatsApp web"(directly in the browser).

Currently, when you click to message a no., it takes you to the screen where it prompts to open the WhatsApp desktop app. So if you don't have WhatsApp desktop client, you need to click "Use WhatsApp web".

I don't use WhatsApp desktop client and guess not many people would be using that as well. So why not take the users directly to "WhatsApp web" as a default behavior. We can provide configurations for people who use WhatsApp Desktop client.

This can be done by adding app_absent=1 parameter to message url