TypeTray: Fix front when back_height is set

Side edges did not fit into side walls.

Resolves: #336
Thanks to https://github.com/RestlessRabbits for reporting!

boxes/generators/typetray.py

@@ -111,6 +111,11 @@ class TypeTray(_TopEdge):
                              callback=[self.xHoles, None, self.gripHole],
                              ignore_widths=[] if bh else [1, 6],
                              move="up")
+        if bh:
+            self.rectangularWall(x, h, [b, "f", t3, "f"],
+                                 callback=[self.mirrorX(self.xHoles, x), ],
+                                 move="up")
+        else:
             self.rectangularWall(x, h, [b, "F", t3, "F"],
                                  callback=[self.mirrorX(self.xHoles, x), ],
                                  ignore_widths=[1, 6], move="up")