How to reproduce:
1. Open the user's project
2. Open the Package Manager Window
3. Install any package e.g. LWRP by clicking the "Install" button in the bottom right
4. Open the version selection dropdown for this package
5. Select a different version X than the one installed
6. Click the "Update to X" button
7. Quickly click on a different version Z
8. Observe the "Updating to Z" button"

Expected result: the button shows the version of the package that was set to install (X)
Actual result: the button shows the version that was last selected (Z)

Reproducible with: 2.1.1
Could not test with: 2.1.0 (cannot select other package versions when one is being installed)

Note: X and Z here are symbols used to represent different versions of the package. Also, the package which is finally installed is the one clicked in the beginning, which is correct