Unused Rotel RMB-1075 Solid State Power Amplifier Channel

I have a 5-channel Rotel RMB-1075 power amplifier that I plan to use only four channels of to drive some outdoor garden speakers, If I don't connect anything to the 5th channel input and don't connect a speaker am I safe? Or should I connect an 8 Ohm 100 Watt power resistor to the output?

I can't speak specifically about your Rotel but I used the center and surround channels only of an Acurus 200FIVE 5-channel amp for about a year and a half with no negative impact at all.