Coverity found a Quality issue: Using invalid iterator

Details:

Coverity Issue ID: 184857
Issue Description: An invalid or past-the-end iterator is being used
Potential Impact: Undefined behavior may result; the program may crash or subtly misbehave.
Coverity checker: INVALIDATE_ITERATOR
Branch: master
File path: /src/mongo/db/shard_role/shard_catalog/uncommitted_catalog_updates.cpp
Line number: Unknown

What Coverity Detected (Main Finding)

Dereferencing iterator "it" though it is already past the end of its container.

The issue can be viewed in Coverity here.

How do I fix this?

Refer to https://wiki.corp.mongodb.com/spaces/HGTC/pages/385852267/Guidance+on+fixing+Coverity+issues for guidance on fixing Coverity issues.