Fix integer overflow in device_list_update.go (#1717)
Fix integer overflow in device_list_update.go (#1717)

Fix #1511
On 32-bits systems, int(hash.Sum32()) can be negative.
This makes the computation of array indices using modulo invalid, crashing dendrite.
Signed-off-by: Loïck Bonniot <46f1a0bd5592a2f9244ca321b129902a06b53e03@lesterpig.com>
matrix-org/dendrite,matrix-org/dendrite,matrix-org/dendrite,matrix-org/dendrite