The answer to your question is here: http://www.question2answer.org/qa/28769?show=28769#q28769
In a recent commit a function was implemented to remove those characters from the core.
If you are not using MySQL 5.5.3+ or maybe you don't want to change your database structure you might also consider switching those characters to HTML before storing them. E.G.: 😁. A filter module should do the trick.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.
May 7, 2020: Q2A 1.8.4 released!