Remove unnecessary null check.
Remove unnecessary null check.

mbebenita/shumway.ts,mbebenita/shumway.ts,hippich/typescript,mbrowne/typescript-dci,fdecampredon/jsx-typescript-old-version,mbebenita/shumway.ts,hippich/typescript,mbrowne/typescript-dci,hippich/typescript,popravich/typescript,mbrowne/typescript-dci,fdecampredon/jsx-typescript-old-version,popravich/typescript,popravich/typescript,fdecampredon/jsx-typescript-old-version,mbrowne/typescript-dci