package/redis: security bump to v6.2.5

package/redis: security bump to v6.2.5

From the release notes:
================================================================================
Redis 6.2.5 Released Wed Jul 21 16:32:19 IDT 2021
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Upgrade urgency: SECURITY, contains fixes to security issues that affect
authenticated client connections on 32-bit versions. MODERATE otherwise.

Fix integer overflow in BITFIELD on 32-bit versions (CVE-2021-32761).
An integer overflow bug in Redis version 2.2 or newer can be exploited using the
BITFIELD command to corrupt the heap and potentially result with remote code
execution.

See https://github.com/redis/redis/blob/6.2.5/00-RELEASENOTES

Signed-off-by: Titouan Christophe <titouanchristophe@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>