Redrawing maps with embedded scalebar increases the layer count by one

[Tamas Szekeres]

Hi list,

When calling mapObj.Draw using mapscript the number of layers increases by
one, an extra __embed__scalebar is added.

See http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1480
for more details.

Tamas Szekeres