Have a 92 cadillac deville 4.9L
I was replacing the rear spark plugs, when i noticed a vacuum line connected to the vacuum tank on the fire wall was cut...running five inches or so out from the bottom of the vacuum tank...the other part of the line runs to the left along the rear side of the engine...i believe it connects to the cruise control servo.

It looks like it was cleanly and neatly cut...i almost think i mightve knocked some sort of connector off the vacuum line when i was pushing my arm around replacing the spark plugs.

What does it do/whats it for? what might be some of the symptoms that it would cause not being connected? I've attached diagrams. The red arrow shows the line im referring to. thanks for any advice.