Adjust some minor changes to the installer and remove rssh

rssh hasnt got any installation candidate in the current Ubunut 20.04 repository. Disabling it is not the final solution, this needs further develop and testing.

install/hst-install-ubuntu.sh

@@ -791,10 +791,15 @@ if [ -d "$withdebs" ]; then
     software=$(echo "$software" | sed -e "s/hestia//")
 fi
 
-if [ "$release" = '16.04' ]; then
+if [ "$release" = '16.04' ] || [ "$release" = '20.04' ]; then
     software=$(echo "$software" | sed -e "s/setpriv/util-linux/")
 fi
 
+if [ "$release" = '20.04' ]; then
+    software=$(echo "$software" | sed -e "s/rssh//")
+fi
+
+
 #----------------------------------------------------------#
 #                 Disable Apparmor on LXC                  #
 #----------------------------------------------------------#
@@ -903,13 +908,15 @@ chmod 755 /etc/cron.daily/ntpdate
 ntpdate -s pool.ntp.org
 
 # Setup rssh
-if [ -z "$(grep /usr/bin/rssh /etc/shells)" ]; then
-    echo /usr/bin/rssh >> /etc/shells
+if [ "$release" != '20.04' ]; then
+    if [ -z "$(grep /usr/bin/rssh /etc/shells)" ]; then
+        echo /usr/bin/rssh >> /etc/shells
+    fi
+    sed -i 's/#allowscp/allowscp/' /etc/rssh.conf
+    sed -i 's/#allowsftp/allowsftp/' /etc/rssh.conf
+    sed -i 's/#allowrsync/allowrsync/' /etc/rssh.conf
+    chmod 755 /usr/bin/rssh
 fi
-sed -i 's/#allowscp/allowscp/' /etc/rssh.conf
-sed -i 's/#allowsftp/allowsftp/' /etc/rssh.conf
-sed -i 's/#allowrsync/allowrsync/' /etc/rssh.conf
-chmod 755 /usr/bin/rssh
 
 
 #----------------------------------------------------------#