ximagesrc: hangs when the streaming xwindow gets closed

This only applies to Linux with X11 and XDamage. Seen on CentOS 7 with GStreamer 1.16

How to reproduce, with two different shells:

shell-1$ xeyes&
shell-2$ gst-launch-1.0 ximagesrc xname=xeyes ! queue ! videoconvert ! xvimagesink
shell-1$ xdotool search xeyes windowkill

In this case, the xeyes window gets killed but nothing happens to GStreamer. By running the same pipeline in an application, most interactions would hang such as

• Sending eos message to the ximagesrc element
• Setting the pipeline state back to NULL