Updated snapraid to the latest release 11.3.

Changelog:

• Fixed handing of Linux devices that have multiple slaves. This affects the smart/list/devices/down commands
• The 'list' command in verbose mode prints the full nanosecond timestamp precision.
• After writing content files also sync their directory.
• Fix a invalid time computation that could result in future scrub dates. Such dates are fixed automatically at the next scrub or sync.

Installed in a virtual machine along with mergerfs.
Created a dummy disk array using mergerfs and tested several different snapraid operations including sync/scrub/fix all of which worked as expected.