Dragging/PNS via ignores connected tracks (disconnects them)
# Description
Dragging a via seems to ignore connected tracks on some layers and does not drag them along. Same happens when the router pushes/shoves other vias around -- they get disconnected.
# KiCad Version
```
Application: Pcbnew
Version: (5.99.0-2694-g4afb2bf0c), release build
Libraries:
wxWidgets 3.0.4
libcurl/7.66.0 OpenSSL/1.1.1g-fips zlib/1.2.11 brotli/1.0.7 libidn2/2.3.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.4/openssl/zlib nghttp2/1.41.0
Platform: Linux 5.7.11-100.fc31.x86_64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
Date: Aug 12 2020 09:22:32
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
Boost: 1.69.0
OCE: 6.9.1
Curl: 7.66.0
Compiler: GCC 9.3.1 with C++ ABI 1013
Build settings:
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=OFF
KICAD_SCRIPTING_PYTHON3=ON
KICAD_SCRIPTING_WXPYTHON=OFF
KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=OFF
KICAD_USE_OCE=ON
KICAD_SPICE=OFF
```
issue