Fix for bad validation in AddSampleLogMultiple

[jhaigh0]

Description of work.

Fixed a typo in AddSampleLogMultiple which caused a crash when reporting an issue where the parse type box was ticked and log types were supplied.

To test:

• Follow example in AddSampleLogMultiple invalid LogType closes workbench #34553 and check that an error about not requiring types when parse type is checked is returned.
• Uncheck parse type, enter incorrect type names, and check that an appropriate error is returned.

Fixes #34553

---

Reviewer

Please comment on the following (full description):

Code Review

• Is the code of an acceptable quality?
• Does the code conform to the coding standards?
• Are the unit tests small and test the class in isolation?
• If there is GUI work does it follow the GUI standards?
• If there are changes in the release notes then do they describe the changes appropriately?
• Are the release notes saved in a separate file, using Issue or PR number for file name and in the correct location?

Functional Tests

• Do changes function as described? Add comments below that describe the tests performed?
• Do the changes handle unexpected situations, e.g. bad input?
• Has the relevant (user and developer) documentation been added/updated?

Does everything look good? Mark the review as Approve. A member of @mantidproject/gatekeepers will take care of it.

[MialLewis]

Fix works, bug no longer present.