add pstoedit as a dependency to inkscape

[Fernan Aguero]

+----[ To FreeBSD Gnome <fernan at iib.unsam.edu.ar> (16.Mar.2005 16:56):
|
| All of them disappear by installing pstoedit. The attached
| patch adds pstoedit to RUN_DEPENDS.
|
+----]

Should I open a PR so that it doesn't get lost ... it's a
tiny and simple patch, though.

Fernan