1994 Toyota Corolla Have you ever seen TWO drain hole in th

I spotted an oil leak problem 2 days ago so I got under the car and found that there is one normal drain plug facing the front of the car tide with no problem, but I also found another hole with something like a rubber plug on it that is located at a 45 degree angle facing the rear on that very oil pan.

The oild leak was from that hole, the piece of rubber was round with about the same diameter of a 14mm drain plug, there is a hole in the middle of that rubber and has treads inside. I've asked from a part shop and a guy who works in jeffy lube, they both said that they've never seen a second hole in the oil pan. I bougth a new drain plug to try to replace that rubber plug, but that particaluar model of drain plug which would fit the normal drain in the front didn't fit that other hole. So I was just wondering if you have any idea about a second hole in the bottom of the oil pan, and where can I find a replacement of that rubber plug thing which I don't know what purpose it served.