As ng stated the clutch pedal already has the proper assist spring on it, if you look directly beyond the mounting hole of the connector you asked about.
The spring you're asking about must be specific to the early cars because I don't recall any such spring in that general vicinity on the later cars. I'm with ng, my first guess would have to do with the hvac system. My second guess would be something to do with the frunk release, although that's a long shot because the frunk release handle is on the pass side on the early cars,