Spark when connect ESC

When i connect my MGM 16018 to my 4s pack, i always have spark when i connect the red wire. I use 5.5mm bullet connector (but same thing occure with Deans), and i always connect the black first, then red, and spark always occure when i conncet red. I know it's normal, but this is dangerous for the controler?

I've read in the MGM manual, that we can install a resistor on the red wire and connect the resistor first to avoid the spark.

Is somebody here do this or everybody don't take care about this?

Thank you!

David