Speakers with two set of inputs are usually dual voice coil models intended to be driven by a right and left channel signal to get a summed mono output (usually shared woofer, dual tweeter). You could post the model number for more help.
If you are hooking up the one speaker wire to both inputs of the speaker (each 8 ohms) in parallel (+ to + and - to -) then the effective impedance of the speaker load is one half - or 4 ohms. If your AVR is rated to drive a 4 ohm load or 2 sets of 8 ohm speakers (can't see manual on the web) then you should be fine. Even if not specified, you can still try it, just carefully watch the temperature of your AVR and make sure it is not getting hot, better ventilation will help if it is in a cabinet.
2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD