Fix to allow user to scroll all the way to bottom of gallery drawer

[nicwells]

Fixes BlueBrain/nexus#3007

Description

Fix to allow scrolling all the way to the bottom of the gallery drawer.

How has this been tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added necessary unit and integration tests.
• I have added screenshots (if applicable), in the comment section.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (1.7.0-M4@5d03a41). Click here to learn what that means.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             1.7.0-M4    #1027   +/-   ##
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  Coverage            ?   65.15%           
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  Files               ?       22           
  Lines               ?      640           
  Branches            ?      137           
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  Hits                ?      417           
  Misses              ?      223           
  Partials            ?        0           

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