Hm, shame, but for those who wonder how to solve it easly. Date processor pattern is a list of patterns, so I could use more than one pattern, what I actually did.
- date:
match:
- key: time
patterns: ["MMM d HH:mm:ss","MMM d HH:mm:ss"]
And that is it. Not very elegant, this pattern should rather be regex not such fixed one, but for this scenario is enough.