Fixing itemsCustom 0 width value

itemsCustom now doesn't require first width to be 0. it will prepopulate
the value taken from the lowest available value

This sort the issue where itemsCustom need to have [0, 2] value.
Now if the variable have items like:
itemsCustom: [[450,2], [600, 5], [900, 10]]
After the modification the itemsCustom will become:
itemsCustom: [[0,2],[450,2], [600, 5], [900, 10]]

Please, modify if required.