Only clone streams on Safari (#2450)
Only clone streams on Safari (#2450)

Only enable the stream cloning behaviour on Safari: it was causing
the audio renderer on Chrome (both desktop and Android) to hang,
causing audio to fail sometimes in Element Call and other Chrome
tabs (eg. YouTube) to fail to play audio.

Fixes https://github.com/vector-im/element-call/issues/267
matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk