[MSA] Fix loading from previous config

[DLu]

Description

I poorly documented the logic here, so I screwed up the reimplementation in a previous PR (#1212)

Checklist

• Required by CI: Code is auto formatted using clang-format
• Extend the tutorials / documentation reference
• Document API changes relevant to the user in the MIGRATION.md notes
• Create tests, which fail without this PR reference
• Include a screenshot if changing a GUI
• While waiting for someone to review your request, please help review another open pull request to support the maintainers

[mergify]

Please target the main branch for development, we will backport the changes to feature/msa for you if approved and if they don't break API.

[codecov]

Codecov Report

Merging #1246 (8101b12) into feature/msa (f12f156) will increase coverage by 2.15%.
The diff coverage is 63.31%.

@@               Coverage Diff               @@
##           feature/msa    #1246      +/-   ##
===============================================
+ Coverage        59.13%   61.27%   +2.15%     
===============================================
  Files              275      274       -1     
  Lines            23732    24925    +1193     
===============================================
+ Hits             14032    15271    +1239     
+ Misses            9700     9654      -46     

Impacted Files	Coverage Δ
...lude/moveit/collision_detection/collision_matrix.h	100.00% <ø> (ø)
...llision_detection/src/collision_octomap_filter.cpp	0.00% <0.00%> (ø)
...src/bullet_integration/bullet_cast_bvh_manager.cpp	51.43% <0.00%> (+0.71%)	⬆️
...bullet_integration/bullet_discrete_bvh_manager.cpp	50.00% <0.00%> (-3.84%)	⬇️
...sion_distance_field/collision_env_distance_field.h	4.77% <ø> (+0.22%)	⬆️
...lision_distance_field/src/collision_env_hybrid.cpp	0.00% <0.00%> (ø)
...ene/include/moveit/planning_scene/planning_scene.h	43.55% <0.00%> (-6.45%)	⬇️
...bot_state/include/moveit/robot_state/robot_state.h	89.96% <ø> (+8.05%)	⬆️
...processing/src/iterative_time_parameterization.cpp	91.99% <0.00%> (-1.25%)	⬇️
...e/moveit/ompl_interface/planning_context_manager.h	100.00% <ø> (ø)
... and 243 more

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