bug: false positive error at argument type

[romshark]

The following catalog.arb file produces 2 false positive errors:

{
	"@@locale": "en",
	"examplemsg": "Your booking for {var0, plural, one {# guest} other {# guests}} on {var1, date, short} is confirmed.",
	"@examplemsg": {
		"placeholders": {
			"var0": {
				"type": "num",
				"description": "cardinal plural",
				"example": "2"
			},
			"var1": {
				"type": "DateTime",
				"description": "time",
				"isCustomDateFormat": true
			}
		}
	}
}

errors:

[{
	"resource": "/Users/romshark/Work/tst/catalog.arb",
	"owner": "arb",
	"code": "missing_other_in_icu",
	"severity": 8,
	"message": "The ICU message format requires a 'other' argument.",
	"startLineNumber": 3,
	"startColumn": 85,
	"endLineNumber": 3,
	"endColumn": 102
},{
	"resource": "/Users/romshark/Work/tst/catalog.arb",
	"owner": "arb",
	"code": "unknown_icu_message_type",
	"severity": 8,
	"message": "Unknown ICU messagetype \"date\"",
	"startLineNumber": 3,
	"startColumn": 91,
	"endLineNumber": 3,
	"endColumn": 95
}]