fix build error caused by wrong ts-strict improvements (#2783)
fix build error caused by wrong ts-strict improvements (#2783)

Co-authored-by: Michael Telatynski <94c9867e567d21b48f1c67ccab9a43d4b4ded84f@gmail.com>
matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk