Bug when "show notifications on all monitors" + notification message has several lines

Issue Description

When an app sends a certain type of multiline notification(*), all the notifications appear on the same monitor (current one receives 3 popups - I have 3 monitors, others monitors 0 popup).

Steps to Reproduce Issue

• install xfce4-notifyd-config 0.9.7.
• set up "show notifications on" to "all monitors"
• run a=$(xrandr | head -n 2) ; notify-send "$a" (*)

Expected Behavior

1 popup on each monitor

Additional Information

...

Versions

• OS distribution and version: LMDE7
• Overall Xfce version: 4.20.1-1 (would be nice to have a simple commeand to get that! xfce4-about does not exist here)
• xfce4-notifyd version (git hash if not a release): 0.9.7-2
• Windowing system (X11/Wayland): X11
• Compositor and version (if Wayland):