Fix Papua-Literacy summary to have correct image URL

[JohnThomson]

This change is 

[gmartin7]

This seems to have been fixed by removing the other url components and just keeping the file name, like most of our brandings. Should this PR be closed?

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @JohnThomson)

[gmartin7]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @JohnThomson)

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src/content/branding/Papua-Literacy/summary.htm line 3 at r1 (raw file):

<div class="vertical">
    <div>Organization: Papua Literacy</div>
    <img src="/bloom/branding/Papua-Literacy/back.png" />

This was fixed in 5.4. (This PR targets 5.5.) Suggest closing...