don't use -M when creating the sogo user on debian

-M was not available in lenny. It is not actually needed since useradd
won't create the homedir when adding a system user (-r)

packaging/debian-multiarch/sogo.preinst

@@ -15,7 +15,7 @@ if [ "$1" == "install" ] || [ "$1" == "upgrade" ]; then
 
   if ! id sogo 1> /dev/null 2>&1; then
     groupadd -f -r sogo
-    useradd -d /var/lib/sogo -g sogo -c "SOGo daemon" -s /usr/sbin/nologin -M -r sogo
+    useradd -d /var/lib/sogo -g sogo -c "SOGo daemon" -s /usr/sbin/nologin -r sogo
   fi
 
   # create mandatory dirs and enforce owner+mode

packaging/debian/sogo.preinst

@@ -15,7 +15,7 @@ if [ "$1" == "install" ] || [ "$1" == "upgrade" ]; then
 
   if ! id sogo 1> /dev/null 2>&1; then
     groupadd -f -r sogo
-    useradd -d /var/lib/sogo -g sogo -c "SOGo daemon" -s /usr/sbin/nologin -M -r sogo
+    useradd -d /var/lib/sogo -g sogo -c "SOGo daemon" -s /usr/sbin/nologin -r sogo
   fi
 
   # create mandatory dirs and enforce owner+mode