While auditing a shard container that is in a shrinking state, the
sharder will merge any shard ranges fetched from the root that cover
the shard's namespace. Previously this was conditional upon the
sharder also fetching the shard's *own* shard range from the
root. However, in extreme circumstances, the shard's own shard range
could become deleted and reclaimed from the root while the shard DB
still needs to shrink to its acceptor ranges. This patch therefore
allows the shard to be updated with potential acceptor ranges from the
root even when its own shard range is not fetched from the root.
Also change the log level from debug to info when logging an update to
a shard's own shard range from root.
Change-Id: I17957cf0ef4936f91e69c6d9ae21551972f0df31
f15b92084f