Fix deselectOption on deselecting the first list entry, if only first entry is selected

[Parama91]

An error occured on deselecting the last selected option, if first in list of options. After adding the missing ' in the function deselectOption to the command, deselection is working and footer is updating fine again. New command: e("option[value='"+e(t).data("val")+"']",this.source).prop("selected",!1)