id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
21447	[Patch] layer=0 proposed in presets, then warned about	Famlam	team	"Followup of https://josm.openstreetmap.de/ticket/21426#comment:6

[https://josm.openstreetmap.de/browser/josm/trunk/resources/data/defaultpresets.xml?rev=18279 defaultspresets] contains 22 instances of `layer` tags being proposed. Each is of the form (with or without `default`):
{{{
#!xml
<combo key=""layer"" text=""Layer"" values=""5,4,3,2,1,0,-1,-2,-3,-4,-5"" length=""3"" values_sort=""false"" />
}}}

However, [https://josm.openstreetmap.de/browser/josm/trunk/resources/data/validator/unnecessary.mapcss#L5 the validator] will complain about `layer=0`.

Simple proposal:
remove `0` as `layer` value in the preset"	enhancement	closed	minor	21.12	Internal preset	latest	fixed	layer 0	skyper