Absolutely normal. Renault cars always have extra cabling and connectors for extra feautures such as esp, electric mirrors, sensors, climate(in case there is a/c installed) etc. So when you want to add a new option they simply have to connect the plugs only. In case you didn't took them while bought the car you can add them later.
This is also helpful with manifacturing process where a single chassis with full cabling is used for all different editions of the vehicle with different add ons