If you're thinking of getting the i3 7100 - don't. You're much better off getting a G4560 as its almost the same power for half the cost.
But I'd opt for the i5 of the 2 you mention.
Overall I'd politely disagree with Coedgy, IMO, the G4560 and the 1050Ti work very well together, and the i3 7100 is almost the same CPU, so it would likely still be a decent pairing, but you may see it become a little more lacklustre in MMO / Multiplayer gaming. And you'd still be better opting for the i5 if you have the budget.
I would also as Techy says, consider the Ryzen at that level if you're already planning on getting a new MB.