It could be perceived as rude and it could've been meant as a joke.
That's the problem with written communication: it's so difficult to know in what emotional state a person has written a message.
It's easy to assume that the friend was rude, because you and him don't always get along, but he could've meant it as banter. It's something I would be likely to say to a close friend, in a teasing way, but only because I know that they fully well know that I don't mean to upset them.
The only way you can find out whether he was rude or not is by asking him, I suppose?
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Live life like a crow:
-Collect shiny things
-Do a sassy walk for no apparent reason
-Scream if you're having fun
-Trust your intuition
-Be playful