Update quick-install.md

doc/quick-install.md

 apt-get update
 ```
 
-### Install all in one run
-
-```sh
-apt-get -o Dpkg::Options::="--force-overwrite" -y install jigasi
-```
-
-If you install that way, you are ready to use Jitsi Meet with SIP gateway.
-
-You can also install the components one by one, as described below.
-
 ### Install Jitsi Meet
 
 ```sh
 dpkg -i --force-overwrite jigasi_1.0-1_amd64.deb
 ```
 
+You need to pass "--force-overwrite" option to dpkg, because the jigasi package patches some of the files in the jitsi-meet package in order to enable the SIP support in Jitsi Meet.
+
 During the installation you'll be asked to enter your SIP account and password. This account will be used to invite the other SIP participants.
 
 ### Reload Jitsi Meet