fix: upgrade http:// to https:// in README.md

README.md

@@ -7,7 +7,7 @@
   * Courses: <https://opencv.org/courses>
 * Docs: <https://docs.opencv.org/4.x/>
 * Q&A forum: <https://forum.opencv.org>
-  * previous forum (read only): <http://answers.opencv.org>
+  * previous forum (read only): <https://answers.opencv.org>
 * Issue tracking: <https://github.com/opencv/opencv/issues>
 * Additional OpenCV functionality: <https://github.com/opencv/opencv_contrib>
 * Donate to OpenCV: <https://opencv.org/support/>
@@ -28,9 +28,9 @@ Please read the [contribution guidelines](https://github.com/opencv/opencv/wiki/
 ### Additional Resources
 
 * [Submit your OpenCV-based project](https://form.jotform.com/233105358823151) for inclusion in Community Friday on opencv.org
-* [Subscribe to the OpenCV YouTube Channel](http://youtube.com/@opencvofficial) featuring OpenCV Live, an hour-long streaming show
-* [Follow OpenCV on LinkedIn](http://linkedin.com/company/opencv/) for daily posts showing the state-of-the-art in computer vision & AI
+* [Subscribe to the OpenCV YouTube Channel](https://youtube.com/@opencvofficial) featuring OpenCV Live, an hour-long streaming show
+* [Follow OpenCV on LinkedIn](https://linkedin.com/company/opencv/) for daily posts showing the state-of-the-art in computer vision & AI
 * [Apply to be an OpenCV Volunteer](https://form.jotform.com/232745316792159) to help organize events and online campaigns as well as amplify them
-* [Follow OpenCV on Mastodon](http://mastodon.social/@opencv) in the Fediverse
+* [Follow OpenCV on Mastodon](https://mastodon.social/@opencv) in the Fediverse
 * [Follow OpenCV on Twitter](https://twitter.com/opencvlive)
 * [OpenCV.ai](https://opencv.ai): Computer Vision and AI development services from the OpenCV team.