Unsafe paste dialog not triggering anymore (1.2.0 regression)

Hi,

I have verified that with xfce4-terminal 1.2.0 the unsafe paste dialog is not triggering anymore if pasting text with newlines via middle mouse button. Pasting with the RMB menu causes the dialog to appear as expected.

Looks like this is cause by commit fd3bd9b0 which, by passing the mouse button click to the terminal, bypasses the check.

I have verified that compiling version 1.2.0 with fd3bd9b0 patched out the unsafe paste dialog works as expected again.

This is happening on FreeBSD, and also on a virtual machine running Arch Linux.

Thanks in advance for any feedback or fixes.