(fix) Bind context to setTimeout

[p-herbert]

Description

There are reported issues with the option delay not working, specifically on mobile (see GitHub Issues 659, 981, 989, 1130, 1136).

Cause

A dragStartFn call loses its context because it is invoked by setTimeout.

Solution

Bind the context.

Note

I do not believe this is necessary for other setTimeout or setInterval calls because they meet one of the following criteria:

1. Their function calls do not require a context.
2. The correct context is already in scope by the variable _this.
3. Private functions already have their context bounded to them.

[kimemin]

this commit saves my life.

---

it works but make errors like this.

k(...).bind is not a function

so I change like this and it works.

_this._dragStartTimer = setTimeout(dragStartFn.bind(_this), options.delay);

[owen-m1]

Please make the necessary changes @p-herbert and then this can be merged

[p-herbert]

@Flame2057 the edit has been made.

Thanks for the fix @kimemin!