That connector is listed on the schematic as X9220B, which is labeled "Pull up resistor fuel level". The Green/Blue wire goes to Fuse #7 which is 4A, and that Green/Blue wire also goes to "battery KL15C" on the ABS unit, and onto the "Position light" (small bulb in the headlight assembly in case the headlight burns out), and also powers the tail light.
The other wire to the connector in the picture is White/blue which goes to the fuel pump assembly connector on the top of the tank called "switched fuel reserve", and onto the dashboard labeled "Fuel reserve".
Apparently there is no resistor connected to the "Pull up resister fuel level" - it is in case that is needed. I hope.
Based on the information in this thread I clipped the connector in the picture above thinking it was the accessory connector X9349B, which should have gone to fuse #2, which is 15A.
So don't do what I did, leave the connector in the picture alone, unless you need a tiny amount of power for a low power accessory.
Sorry! My fault, i had a more precise look at the wiring plan

Coffee is right, the connector is X9220B and not X9349B!
So plug 83300402344 fits to X9220B and not to X9349B.
Nevertheless i think i can use it for connecting an USB-charger, fuse which is 4A should be ok.
So again the question: Does anyone know where to find X9349B which shall be the connector for additional accessory?