fix(render): disable alpha flag by default for rctx
fix(render): disable alpha flag by default for rctx

stardazed/stardazed-tx,stardazed/stardazed-tx,zenmumbler/libzm,stardazed/stardazed,zenmumbler/stardazed-tx,stardazed/stardazed,stardazed/stardazed-tx,zenmumbler/stardazed-tx,zenmumbler/stardazed-tx,zenmumbler/libzm,zenmumbler/libzm,zenmumbler/stardazed-tx,zenmumbler/libzm