Cannot enter multiple property values with CSS code hints.

[RaymondLim]

1. In a CSS rule select background-position from the code hints.
2. Select any property value when prompted.
   Result: Selected property value is inserted with a semicolon at the end (issue CSS code hints should not auto append a semicolon after selecting a property value. #2625).
3. Hit backspace and then enter a space.
   Result: CSS code hints just show the property value you already entered and you can't enter another property value.

[RaymondLim]

Reassign it to myself since it is closely related to #2682.

[RaymondLim]

FBNC to @dangoor.

[dangoor]

Confirmed that you can now use hinting to pick another property value.