Fix bug in dictionaries install tool

[vkbo]

Summary:

This PR fixes a bug where the enchant config dir returned by the enchant package does not exist by default, causing a crash when trying to install additional spell check dictionaries.

Related Issue(s):

Closes #1874

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed