Your redirection code seems perfect to me. You may be perplexed at another area.
As per my knowledge, there may be an issue with Google Webmasters tools alternatively we can say Google Search Console. To track your website performance, you might have entered website URL with HTTPS (https://www.example.com) and that might be indicating Google search to display HTTPS URLs for your website. Search Console gives significant idea to Google Search to display proper URL in organic search result.
Now let us talk about importance of SSL certificate for website. Whether you've eCommerce website or a simple blog, every data traveling between browser and server needs to be protected, SSL certificate gives that facility. If you are thinking, why does my blog need SSL when it is not processing payment or allowing users to login?
Let me clear your view: It is obvious that every website owners want to rank top of the Google, here also SSL can be helpful as Google has given elucidated intention to push organic ranking for SSL secured website. So it is advisable to choose any cheap price certificate for your website instead of changing URL on Search Console.
Useful URLs:
Https to http redirect using htaccess
https://www.cheapsslshop.com/blog/google-says-companies-frivolous-attitude-on-https
https://webmasters.googleblog.com/2014/08/https-as-ranking-signal.html