Prevent Loop in BRepBuilderAPI_Transform

- if a scale transform with scale = 0 is passed to
  BRepBuilderAPI_Transform, it will loop forever.
  If Page.keepUpdated is false, and Views have not yet
  been executed (ex at load time), Views will have a
  0.0 x 0.0 bbox and if Autoscale is true, a scale of
  0.0 will be used in fit-to-page.

src/Mod/TechDraw/App/DrawProjGroupItem.cpp

@@ -183,6 +183,10 @@ double DrawProjGroupItem::getScale(void) const
     auto pgroup = getPGroup();
     if (pgroup != nullptr) {
         result = pgroup->Scale.getValue();
+        if (!(result > 0.0)) {
+            Base::Console().Log("DPGI - %s - bad scale found (%.3f) using 1.0\n",getNameInDocument(),Scale.getValue());
+            result = 1.0;                                   //kludgy protective fix. autoscale sometimes serves up 0.0!
+        }
     }
     return result;
 }