CLOUDSTACK-6854: Fix inconsistent IPv6 address formats

fc00:0003:1373::0002 should be treated the same as fc00:3:1373::2.
(cherry picked from commit dfe20f34f2e72335586b0e014ba1f91aa4ed473e)
Changed logic for copying snapshot from S3 to NFS staging store to prevent needless failure.

Signed-off-by: Daan Hoogland <daan@onecht.net>
(cherry picked from commit 736bf540e8ef759a101d221622c64f3b3c3ed425)