Line ending with escaped colon (\:) with no speaker do not generate line ids

[mattdavisgames]

Describe the bug
When a line with no speaker ends with \:, translation fails to generate a line id for it.
Example line:
But here's how it's supposed to work\:

Affected version

• Dialogue Manager version: 3.10.4
• Godot version: 4.6.1

To Reproduce
Steps to reproduce the behavior:

1. Add the following line to a dialogue:
   But here's how it's supposed to work\:

2. Click Translations -> Generate line IDs for file

3. Observe that no line id is generated for the line.

Expected behavior
At step (3), a line id is expected to be generated for the line.

(Also thanks Nathan for your hard work on this amazing plugin!)