Autcomplete not working for multiline strings in Editor

[CitrusWire]

Godot version:
3.2.3

OS/device including version:
Win 7

Issue description:
Multiline scripts don't autocomplete properly in the editor.

Steps to reproduce:
(With the | representing where the cursor is.)

Should be able to type:
"""
and have it automatically create:
"""|"""

Currently you have to type all six and you get back:

""""""|

Minimal reproduction project:

[Paulb23]

Should be fixed by #45393