MLK Jr was unequivocally non-violent. That quote was in the context of explaining the root cause of the rioting, not condoning or endorsing it.
Don't trust anyone trying to tell you MLK Jr would have supported violent protests.
They are either trying to manipulate you or sadly ignorant (or both, of course). In either case they have it wrong, in terms of history and in the implication that violent protest will lead to any kind of progress or justice.
listen to your fellow humans
When you see news about a riot, your first instinct should be to ask why? What are they rioting about? What was being said that led to this situation? Were people listening? How did they respond?
Not make a judgement of them.
This is where media has great power in controlling the narrative. If they don’t report on what happened prior to the riots (ex: peaceful protests, calls to representatives for action, etc), then it becomes very hard to see rioters as human beings with a voice.
Edit: note that I’m not making a judgement on OP. I writing this because I often see this reaction to riots and people often take away the wrong message both ways.