KeyDB v6.2.1

This release of KeyDB is at parity with Redis 6.2.6. In addition, the following changes were included:

• Systemd support for release packages
• Fixes to buffer overflows in the BITOP SHIFT and CRON commands
• Server times are now computed on a seperate thread to improve performance
• Now enforces syslog identity and facility as soon as possible
• Removed erroneous use of LOG_... flags when using syslog
• Fixed erroneous #endif leading to build errors on some platforms
• Fixed the incorrect counting of client connections

Issues resolved:
#355, #370