Geo: Don't show external link icon for current node

What does this MR do?

The "Open Projects" page should be visited on the Geo node itself. So that link can be "external", from current node's point of view. That's why it had the external-link icon.

But the button for the current node is not external, so for current-node it should not show this icon.

Screenshots

On primary	On secondary

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• EE specific content should be in the top level /ee folder
• For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?
• Security reports checked/validated by reviewer