Fail to parse unknown & none strings for event.Type/Severity types

[yhabteab]

Fail to parse "type":"unknown" and "severity":"none" instead of parsing them as event.TypeUnknown and event.SeverityNone.

[oxzi]

LGTM, thanks.

Due to the iota type mixed with the obscured type_string.go file, I needed a moment to understand the implications. Especially as _Type_index contains an entry for typeMax, internal. However, due to range typeMax, the ParseType function cannot parse "internal" to typemax.

icinga-go-library/notifications/event/type_string.go

Line 27 in 046489a

const _Type_name = "unknownacknowledgement-clearedacknowledgement-setcustomdowntime-enddowntime-removeddowntime-startflapping-endflapping-startincident-agemutestateunmuteinternal"