Remove quickpost

[DrumsnChocolate]

The quickpost once was a feature that was very nice to use, and added value for most users. In the past years, it has become outdated in its implementation, accumulated bugs, and many members report seeing little benefit to the feature. There are widely used alternatives like WhatsApp that are more complete and at least as easy to use, making the quickpost obsolete. It makes sense to remove this, since it is a technical burden that does not seem worth the cost of fixing or maintaining.