Fix "Prefer format() over string interpolation operator" issue

[goanpeca]

This pull request automatically fixes all occurrences of the following issue:

Issue type: Prefer format() over string interpolation operator
Issue details: https://www.quantifiedcode.com/app/project/gh:spyder-ide:qtpy?groups=code_patterns/%3A4ACGxFj1

To adjust the commit message or the actual code changes, just rebase or cherry-pick the commits.
For questions or feedback reach out to cody@quantifiedcode.com.

Legal note: We won't claim any copyrights on the code changes.

Cheers,
Cody - Your code quality bot

[goanpeca]

@spyder-ide/core-developers testing a new tool called quantified code.

Its pretty cool :-)

[Nodd]

The tool looks cool, but I'd reject this pull request because:

1. String interpolation is not bad for small string like these
2. It's not what a human would write, the tool was careful to keep the exact same functionality but in both cases {0} is enough.

[ccordoba12]

I agree with @Nodd: using {0} is enough in both cases.

[ccordoba12]

I did the changes myself to be able to release 1.0.2 (which I need to better support QtWebEngine in 5.6 :-)