BF: fix path to the exim log on Debian systems (/var/log/exim4)

config/jail.conf

@@ -501,13 +501,13 @@ logpath = %(solidpop3d_log)s
 [exim]
 
 port   = smtp,465,submission
-logpath = /var/log/exim/mainlog
+logpath = %(exim_main_log)s
 
 
 [exim-spam]
 
 port   = smtp,465,submission
-logpath = /var/log/exim/mainlog
+logpath = %(exim_main_log)s
 
 
 [kerio]

config/paths-common.conf

@@ -22,6 +22,7 @@ syslog_user =
 # from /etc/audit/auditd.conf
 auditd_log = /var/log/audit/audit.log
 
+exim_main_log = /var/log/exim/mainlog
 
 nginx_error_log = /var/log/nginx/error.log
 

config/paths-debian.conf

@@ -30,6 +30,7 @@ apache_error_log = /var/log/apache2/*error.log
 
 apache_access_log = /var/log/apache2/*access.log
 
+exim_main_log = /var/log/exim4/mainlog
 
 # was in debian squeezy but not in wheezy
 # /etc/proftpd/proftpd.conf (SystemLog)