Support PHP installed from Debian Packages System.

conf/install_upgrade_roundcube.conf.sample

@@ -47,7 +47,7 @@ IPV6=""
 # - Note: it's not the 'DocumentRoot' directory, but the directory where
 # -       the 'DocumentRoot' Directory lives.
 # -
-# - Defaults to '/var/www/webmail/$WEBSITE_NAME'
+# - Defaults to '/var/www/$WEBSITE_NAME'
 # -
 #WEBSITE_BASEDIR=""
 
@@ -100,6 +100,15 @@ IPV6=""
 # -
 #CERT_ChainFile=""
 
+
+# - Is PHP installed from debian package system ?
+# -
+# - Boolean, possible values are 'true', 'false'
+# -
+# - Defaults to 'false'
+# 
+#PHP_DEBIAN_INSTALLATION=""
+
 # - Type of PHP installation.
 # -
 # - Possible values are: 'php_fpm' , 'fcgid' , 'mod_php