fix: edit svg to take current color

[NeleRiediger]

Description

fixes #415
Makes the icon of the settings tab for crosslinking default values use the correct colors.

Changes

Edited the svg of that icon

Testing

Look at the icon and compare its color to the others, hover over it and klick on the button so the tab is selected. Make sure the color-behavior of this button and its icon matches the other buttons.

PR checklist

Development

• If necessary, I have updated the documentation (README, docstrings, etc.)
• If necessary, I have created / updated tests.

Mergeability

• main-branch has been merged into local branch to resolve conflicts
• The tests and linter have passed AFTER local merge
• The backend code has been formatted with black
• The frontend code has been formatted with pnpm format and checked with pnpm lint

Code review

• I have self-reviewed my code.
• At least one other developer reviewed and approved the changes

[Elena-kal]

Nele du bist toll, dankeeee