Define uninitialized values for send in subviewport container.

[fire]

I was getting compiler errors about the send not being initialized.

[Sauermann]

send shouldn't be removed, because setting that variable is the intention of the virtual call. (resolved)
On which compiler do you experience the problem? It hasn't yet caused any problems within the usual Github checks.

[KoBeWi]

This is a common pattern if the variable is used only after virtual call and is used in other places. E.g.

godot/core/math/a_star.cpp

Lines 395 to 398 in e001bc7

	real_t scost;
	if (GDVIRTUAL_CALL(_estimate_cost, p_from_id, p_to_id, scost)) {
	return scost;
	}

It's odd that you'd get a warning only in one case.

[fire]

Close because I can't recreate the bug.