set_line () method in TextEdit leads to collapse.

[OlexiyKravchuk]

Godot version:
Godot_v3.2.2-stable_win64

OS/device including version:
Win7 (GLES2)

Issue description:
set_line () method in TextEdit leads to collapse.

var TE = $"TextEdit"
TE.set_line(TE.get_line_count(), "....STR....")

[OlexiyKravchuk]

I think I figured out that the reason is that tab.get_line_count () is always greater than zero.
But if you specify in the parameter the line number in the set_line () method, the number of which is not, then this failure will occur.
That is, more secure processing is needed in case the specified line is not present.