tippy: Hide tooltip for inline images if the reference is removed.
tippy: Hide tooltip for inline images if the reference is removed.

Spamming the `s` shortcut when hovered on an image can cause the
tooltip to be displayed at the top left corner. This is caused by
original reference of the tooltip being removed from DOM. The
re-rendering is happening so quickly that tippy is not able to hide
the tooltip in time.

rht/zulip,andersk/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,rht/zulip,zulip/zulip,rht/zulip,andersk/zulip,andersk/zulip,rht/zulip,rht/zulip,zulip/zulip,zulip/zulip,andersk/zulip,andersk/zulip,andersk/zulip,zulip/zulip,zulip/zulip,andersk/zulip