Add example configuration for fail2ban

From Arnd Brandes. (#2229)

Scripts/fail2ban/sogo-filter.conf

@@ -0,0 +1,20 @@
+# /etc/fail2ban/filter.d/sogo.conf
+#
+# Fail2Ban configuration file
+# By Arnd Brandes
+# SOGo
+#
+
+[Definition]
+# Option: failregex
+# Filter Ban in /var/log/sogo/sogo.log
+# Note: the error log may contain multiple hosts, whereas the first one
+# is the client and all others are poxys. We match the first one, only
+
+failregex = Login from '<HOST>.*' for user '.*' might not have worked
+
+# Option: ignoreregex
+# Notes.: regex to ignore. If this regex matches, the line is ignored.
+# Values: TEXT
+#
+ignoreregex =

Scripts/fail2ban/sogo-jail.local

@@ -0,0 +1,9 @@
+[SOGo]
+enabled = true
+port = http,https
+# in proxy-free setup this would be:
+# port = 20000
+filter = sogo
+logpath = /var/log/sogo/sogo.log
+maxretry = 5
+