What was the home team for the 2nd leg for the match having a 1st leg score of 2-1?
CREATE TABLE "winners_knockout" (
  "home_1st_leg" text,
  "home_2nd_leg" text,
  "1st_leg" text,
  "2nd_leg" text,
  "aggregate" text
);
SELECT "home_2nd_leg" FROM "winners_knockout" WHERE "1st_leg"='2-1';