psimage: fix -B+t>title> issue

[joa-quim]

Fix #5635

Assites-by: Claude Opus 4.7

[Esteban82]

It works. I got this image with this command:

gmt image @needle.jpg -Dx0/0+w7c -JM12c -JZ14c -p200/30 -B0 -B+w1p+gred3+t"title" -png plot

[joa-quim]

And if you do not use -B0 you should see no frame.

[joa-quim]

But things are not completely right (and Claude warned me about it). The title is not rotated.

[Esteban82]

But things are not completely right (and Claude warned me about it). The title is not rotated.

Right. I didn't pay attention to that.

[joa-quim]

The title angle is now fixed.

This PR now causes test/grdmix/grdmix.sh test to fail. But I think the grdmix.ps baseline is wrong because it misses the frame that is implied by that script using -B0. So, it turns out that apparently we killed two bugs with one stone.

[Esteban82]

The title angle is now fixed.

I'm affraid that I try it and I am getting the same figure.

[joa-quim]

Maybe you didn't get the updated branch? Can't retest right now as I'm debugging something else in another branch.