Cleanup in gcodeplater

gcodeplater.py

@@ -77,12 +77,12 @@ class GcodePlater(Plater):
     # Initial implementation should just print the objects sequentially,
     # but the end goal is to have a clean per-layer merge
     def export_to(self, name):
-        with open(name, "w") as f:
         models = self.models.values()
         last_real_position = None
         # Sort models by Z max to print smaller objects first
         models.sort(key = lambda x: x.dims[-1])
-            for model in models:
+        with open(name, "w") as f:
+            for model_i, model in enumerate(models):
                 r = model.rot  # no rotation support for now
                 if r != 0:
                     print _("Warning: no rotation support for now, "