Ubuntu packages: libraries in a different location than Kicad expects them

Description

I'm using the nightly Ubuntu packages and Kicad seems to expect its libraries in /usr/lib/kicad-nightly/share/kicad/library/

But the symbols package puts them in /usr/share/kicad-nightly/library

Steps to reproduce

1. Remove the file sym-lib-table
2. Open schematic editor
3. "Configure Global Symbol Library Table" dialogue opens.

Expected behaviour: Option "Copy global symbol library table (recommended)" detects installed libraries and works. Actual behaviour: The default option is greyed out.

KiCad Version

Version: 5.99.0-unknown-4920692bcd~125~ubuntu20.04.1, release build

Libraries:
	wxWidgets 3.0.4
	libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3

Platform: Linux 5.4.0-72-generic x86_64, 64 bit, Little endian, wxGTK, plasma, x11

Build Info:
	Date: Apr 15 2021 08:03:08
	wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.71.0
	OCC: 7.3.0
	Curl: 7.68.0
	ngspice: 31
	Compiler: GCC 9.3.0 with C++ ABI 1013

Build settings:
	KICAD_SCRIPTING=ON
	KICAD_SCRIPTING_MODULES=ON
	KICAD_SCRIPTING_PYTHON3=ON
	KICAD_SCRIPTING_WXPYTHON=ON
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
	KICAD_SCRIPTING_ACTION_MENU=ON
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON