Change 6.2.0rc1 to 6.2.0rc2 in version_switch.js

[maxrjones]

Description of proposed changes

Changes the 6.2.0rc1 switch to 6.2.0rc2 in version_switch.js.
Addresses #5191

Reminders

• Make sure that your code follows our style. Use the other functions/files as a basis.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Describe changes to function behavior and arguments in a comment below the function declaration.
• If adding new functionality, add a detailed description to the documentation and/or an example.

[maxrjones]

@seisman, do you think it is better to add a new switch or replace 6.2.0rc1 with 6.2.0rc2 as done in this PR?

[seisman]

Looks good. Just a reminder that, we may want to delete the 6.2.0rc1 directory in the gh-pages branch to reduce the branch size.