fix typos in github urls

Checklist before submitting

[ ] Did you discuss your submission before?
[ ] Does your submission is cleanly rebased on top of the master branch?
[ ] Does your submission pass tests?
[ ] Have you lint your code locally before submission?
[ ] Have you added tests for all new code you've added, thus at least improving the coverage?
[ ] Does your code follow the style of this project?
[ ] Did you perform a self-review of your code?
[ ] Have you commented your code, particularly in hard-to-understand areas?
[ ] Have you made corresponding changes to the documentation?
[ ] Do your changes generate no new warnings?

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Fixes ...