Adjust for new NLSR configuration format

Also removes 20.04 LTS from officially supported distros
as it no longer runs "out of the box" due to recent commits.

Refs #5366, #5367

Change-Id: I30577bd9010e7597e00a8826d5e31d5487ef14e2
diff --git a/minindn/apps/nlsr.py b/minindn/apps/nlsr.py
index ffffd76..de23aa3 100644
--- a/minindn/apps/nlsr.py
+++ b/minindn/apps/nlsr.py
@@ -309,8 +309,8 @@
 
     def __editAdvertisingSection(self):
 
-        self.node.cmd('{} -d advertising.prefix'.format(self.infocmd))
-        self.node.cmd('{} -s advertising.prefix -v {}{}-site/{}'
+        self.node.cmd('{} -d advertising'.format(self.infocmd))
+        self.node.cmd('{} -s advertising.{}{}-site/{} -v 0'
                       .format(self.infocmd, self.network, self.node.name, self.node.name))
 
     def __editSecuritySection(self):