v.to.db: allow (unitless) calculation of perimeter in XY location (backport from trunk)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@68133 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.to.db/areas.c

@@ -40,7 +40,7 @@ int read_areas(struct Map_info *Map)
 	if ((options.option == O_COMPACT) || (options.option == O_FD) ||
 	    (options.option == O_PERIMETER)) {
 	    perimeter = Vect_get_area_perimeter(Map, area_num);
-	    if (G_projection() != PROJECTION_LL)
+	    if (G_projection() != PROJECTION_LL && G_projection() != PROJECTION_XY)
 		    perimeter = perimeter * G_database_units_to_meters_factor();
 	}