[FIX] web: remove enforceFocus method from bootstrap modal

since it is conflicting with other non bootstrap element

This method trigger the focus event when clicking inside the modal, causing a blur event on other widgets resulting in unwanted problem. Typical case is for the jquery datetimepicker where we try to open a select element which will close right after.

DO NOT FORWARD PORT TO MASTER since we don't use jquery datetimepicker in master and bug doesn't exist in master