Ruby on Rails course, Installing PostgreSQL lesson: Remove extra word in sentence

[evan-ting]

Because

There was a redundant word in a sentence that had to be removed in order to correct the grammar of said sentence.

This PR

• Removed the word 'fix', as the word 'resolve' is all that is needed to make the sentence grammatically correct

Issue

Closes #XXXXX

Additional Information

This is my first contribution to The Odin Project's curriculum :)

I am really enjoying the curriculum, and I am happy to be able to help improve it, even if it's only a minor change.

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide