doc/quickstart: add software-properties instruction

This is indicated in the `Installation` section, but not in the
quickstart, and it felt like a valid addition, here, too.

diff --git a/doc/userguide/quickstart.rst b/doc/userguide/quickstart.rst
index 899de35fd4c3302bfdf42862aa02c4f441d2dcda..d2bdda0fe8c0d14ba063d6eebbf6372f43a3ec28 100644 (file)
--- a/doc/userguide/quickstart.rst
+++ b/doc/userguide/quickstart.rst
@@ -11,6 +11,7 @@ It's assumed that you run a recent Ubuntu release as the official PPA can then
 be used for the installation. To install the latest stable Suricata version, follow
 the steps::
 
+    sudo apt-get install software-properties-common
     sudo add-apt-repository ppa:oisf/suricata-stable
     sudo apt update
     sudo apt install suricata jq