Bug#504136: thuban: Changing map projections results in error

[Sebastiaan Couwenberg]

Control: found -1 1.2.2-3+b1

This issue is still present in the most current version.

I've not been able to reliable reproduce the error with the steps
provided in the original report, but something very similar.

My steps to reproduce the issue:

Select Map -> Projection to open the Map Projection window.

Enter a random name, an select one of these projections:
- <Unknown>
- Transverse Mercator
- Lambert Conic Conformal
And click the Try button.

This will cause the error popup. Selecting another projection will not
cause the error popup.

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GnuPG: 0xE88D4AF1 (new) / 0x77A975AD (old)