Put diencephalon to correct position in area hierarchy

src/res/ext/bigbrain.json

@@ -689,7 +689,11 @@
                       ]
                     }
                   ]
-                },
+                }
+              ]
+            }
+          ]
+        },
                 {
                   "name": "diencephalon",
                   "children": [
@@ -855,10 +859,6 @@
                     }
                   ]
                 }
-              ]
-            }
-          ]
-        }
       ]
     },
     {