rename exported prefab instance to fbx name

- otherwise if name gets incremented on export, change won't be
reflected in prefab instance name

Author: vkovec

Assets/FbxExporters/Editor/ConvertToModel.cs

@@ -180,6 +180,7 @@ public static GameObject Convert (
                             prefabFileName, fbxFullPath));
                 }
 
+                toConvert.name = Path.GetFileNameWithoutExtension (fbxFullPath);
                 return toConvert;
             }