[Bug] MOUSE_UP action was ignored if any other mouse button was pressed

[ToTheHit]

Steps to reproduce:

1. Press on port by left mouse button. Message "MOUSE DOWN" is sent to console
2. Press any other mouse button (right, middle, etc.). Message "MOUSE DOWN" is sent to console again.
3. Release "other" mouse button -> message "MOUSE UP" in console.
4. Release left mouse button -> nothing

Result: we have 2 messages "MOUSE DOWN" and 1 message "MOUSE UP"

Code example: https://codesandbox.io/s/bug-react-diagrams-m2b611?file=/src/DragLinkState.js