MessageInputTextView: Fix GTK warning when closing chat control

Fixes #10146
3 jobs for message-input-drag-dest-fix in 4 minutes and 27 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
passed #18951
run-appdata

00:00:06

passed #18950
run-tests

00:04:07

 
  Build
passed #18952
run-build

00:00:13