Fix zone rendering for kicad >= 7.0

Old algorithm that used zone min thickness in addition to polygon
was retired in 7.0

Author: qu1ck

InteractiveHtmlBom/ecad/kicad.py

@@ -734,6 +734,8 @@ def parse_zones(self, zones):
                 if (hasattr(zone, 'GetFilledPolysUseThickness') and
                         not zone.GetFilledPolysUseThickness()):
                     width = 0
+                if KICAD_VERSION[0] >= 7:
+                    width = 0
                 zone_dict = {
                     "polygons": self.parse_poly_set(poly_set),
                     "width": width,