Just upgraded my late 2013 MBP to a larger SSD. Went smoothly, happy with the extra space. Did a 'clean' install of Mojave, then used Migration Assistant to move my stuff to the new drive. After using it for a bit, noticed an icon on the menu bar between finder and notification that I had not seen before. A little round colorful one, which did not seem to do anything when I clicked it. Can anyone tell me what it is? Did I make a mistake removing it?