Don't tweak the SSH config if persistence is enabled

And also ensure we run the initial configuration only once so that
the user can override our initial changes.

Fixes #22

kali-config/common/includes.chroot/usr/lib/live/config/0031-kali-user-setup

@@ -19,6 +19,11 @@ configure_kaboxer() {
     adduser kali kaboxer
 }
 
+# Avoid configuring multiple times in case persistence is enabled
+if [ -e /var/lib/live/config/kali-user-setup ]; then
+    exit 0
+fi
+
 # Set "kali" as password for the user kali
 usermod -p 'AqLUsDitNnTsw' kali
 
@@ -27,3 +32,6 @@ configure_zsh
 
 # Add kali user to the kaboxer group
 configure_kaboxer
+
+# Remember that this script has been run
+touch /var/lib/live/config/kali-user-setup

kali-config/common/includes.chroot/usr/lib/live/config/1165-fix-openssh-server

@@ -1,4 +1,10 @@
 #!/bin/sh
 
+if grep -qw persistence /proc/cmdline; then
+    # With persistence enabled, don't modify the configuration, let the
+    # user be in charge...
+    exit 0
+fi
+
 # Allow PasswordAuthentification in sshd config
 sed -i -e 's|#\?\(PasswordAuthentication\) no|\1 yes|' /etc/ssh/sshd_config