DAOS-18863 mercury: Change handling of connection reset for ucx.

[jgmoore-or]

Test-provider: ucx+dc_x
Test-provider-hw-large: ucx+dc_x
Test-provider-hw-medium: ucx+dc_x
Test-provider-ucx: ucx+dc_x
Skip-func-hw-test-medium-verbs-provider: true
Skip-func-test-vm: true
Allow-unstable-test: true

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Ticket title is 'aggregation/space_rb.py:SpaceRb.test_space_rb - engine crash destroying pool'
Status is 'In Progress'
Labels: 'ci_master_weekly,scrubbed_2.8,triaged,ucx_provider,weekly_test'
https://daosio.atlassian.net/browse/DAOS-18863

[daosbuild3]

Test stage Unit Test with memcheck completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18338/2/testReport/

[daosbuild3]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18338/2/execution/node/1240/log

[daosbuild3]

Test stage Functional Hardware Medium completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18338/3/execution/node/677/log

[daosbuild3]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18338/3/execution/node/718/log

[daosbuild3]

Test stage Functional Hardware Large completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18338/3/execution/node/759/log

[daosbuild3]

Test stage Functional Hardware Large MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18338/3/execution/node/800/log