Useless assignment to local variable in the src/core/xfa/template.js file

[Snuffleupagus]

The following code is flagged as dead (since it's replacing rather than updating the existing Object):

pdf.js/src/core/xfa/template.js

Lines 2336 to 2339 in 4483cba

	availableSpace = {
	width: this.w === "" ? availableSpace.width : this.w,
	height: this.h === "" ? availableSpace.height : this.h,
	};

according to the alert in https://github.com/mozilla/pdf.js/security/code-scanning/103?query=ref%3Arefs%2Fheads%2Fmaster

Looking at the surrounding code, I can see a couple of possibilities here:

1. This is indeed just dead code, which should be removed.
2. The code should be moved up, and placed just above the previous block instead.
3. There should be other, more invasive, changes made to this code...

/cc @calixteman Which solution is correct here?
Assuming it's either option 1 or 2, I can submit a patch to fix this.

[calixteman]

It's dead code.