CADExchanger add on intercepts exports for matching types

[brianredbeard]

After installing the CADExchanger (CE) addon it's attempting to funnel all exports through CE, even for types FreeCAD can handle natively.

I discovered this when attempting to export an STL file where CE failed:

12:27:09  executing /home/bharrington/Downloads/cadexchanger_3.10.0_build14619_lin64/bin/ExchangerConv -i "/tmp/tmpuwltx6ng.brep" -e "/home/bharrington/Downloads/new_corexy_brackets.stl"
12:27:09  Error during CADExchanger conversion
12:27:09  CADExchanger output:
CAD Exchanger 3.10.0 build 14619 (cadexchanger.com)
12:27:09  

Additionally, since changes made to the CE configuration currently require a complete restart of FreeCAD, this amplifies the annoyance by requiring disabling CE. restarting, and exporting.

This occurred using FreeCAD 0.19, Libs: 0.19R24291