PCB editor: dragging footprints is broken

Description

Dragging footprints was broken in the recent days and is now always a no-op.

Steps to reproduce

1. Place a footprint
2. try to drag it (d) somewhere else
3. place it

Expected: traces follow the footprint, footprint is placed at the desired location (if no collisions occurred)

Actual: traces aren't dragged at all, footprint snaps back to the original position

KiCad Version

Application: KiCad PCB Editor

Version: (6.0.0-rc1-485-g232b39a321), release build

Libraries:
	wxWidgets 3.0.5
	libcurl/7.79.1 OpenSSL/1.1.1l zlib/1.2.11 brotli/1.0.9 libidn2/2.3.2 libpsl/0.21.0 (+libidn2/2.3.0) libssh2/1.10.0 nghttp2/1.43.0 librtmp/2.3 OpenLDAP/2.4.59

Platform: Linux 5.16.0-rc3-amd64 x86_64, 64 bit, Little endian, wxGTK, XFCE, x11

Build Info:
	Date: Dec 15 2021 22:22:44
	wxWidgets: 3.0.5 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.5.1
	Curl: 7.79.1
	ngspice: 35
	Compiler: GCC 11.2.0 with C++ ABI 1016

Build settings:
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON