Legend.symbolHeight do not accept 0

[KacperMadej]

Expected behaviour

No visible symbol when symbolHeight is set to 0.

Actual behaviour

highcharts/ts/Core/Legend/Legend.ts

Lines 745 to 746 in ff6ddd4

	legend.symbolHeight =
	options.symbolHeight || legend.fontMetrics.f;

Live demo with steps to reproduce

https://jsfiddle.net/BlackLabel/5u18nvym/

Workaround

Use a value close to 0 instead - so something like 0.001 will be ok.
https://jsfiddle.net/BlackLabel/5u18nvym/1/