Update quick-install.md (#2657)

Add potential additional package to install, tested on fresh Debian 9 installation.

doc/quick-install.md

 apt-get update
 ```
 
+(If you get an error:
+E: The method driver /usr/lib/apt/methods/https could not be found.
+run:
+```sh
+apt-get install apt-transport-https
+```
+)
+
 ### Install Jitsi Meet
 
 Note : Something to consider before installation is how you're planning to serve Jitsi Meet. The installer will check if Nginx or Apache is present (with this order) and configure a virtualhost within the web server it finds to serve Jitsi Meet. If none of the above is found it then configures itself to be served via jetty. So if for example you are planning on deploying Jitsi Meet with a web server, you have to make sure to install the server **before** installing jitsi-meet.