Fix a permission error that we should have fixed ages ago.

Add this to your merge proposal:
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lp:~raoul-snyman/openlp/permission-error-2.4 (revision 2645)
[SUCCESS] https://ci.openlp.io/job/Branch-01-Pull/1676/
[SUCCESS] https://ci.openlp.io/job/Branch-02-Functional-Tests/1587/
[SUCCESS] https://ci.openlp.io/job/Branch-03-Interface-Tests/1525/
[SUCCESS] https://ci.openlp.io/job/Branch-04a-Windows_Functional_Tests/1290/
[SUCCESS] https://ci.openlp.io/job/Branch-...