Assert in Symbol Selection

1. Add symbol 'A'
2. Open Symbol Library Browser
3. Select something
4. Start typing until the filter eliminates all options
5. Assert

2022-08-23_14-27-50

KiCad Version

Application: KiCad Schematic Editor

Version: (6.99.0-3008-g7e030466f6-dirty), debug build

Libraries:
	wxWidgets 3.0.5
	FreeType 2.11.1
	HarfBuzz 2.7.4
	FontConfig 2.13.1

Platform: Linux 5.15.0-41-lowlatency x86_64, 64 bit, Little endian, wxGTK, KDE, x11

	wxWidgets: 3.0.5 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.5.2
	Curl: 7.81.0
	ngspice: 30
	Compiler: Clang 14.0.0 with C++ ABI 1002

Build settings:
	KICAD_SPICE=ON
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE_ADDRESS=OFF
	KICAD_SANITIZE_THREADS=OFF