Gracefully handle missing Baudrate setting in DCF (#492)

The CiA306 spec is not quite clear on which fields are mandatory
within the DeviceComissioning section.  Thus it should be assumed that
the two options handled here could be missing.  Instead of raising an
exception, ignore the absence of the Baudrate setting.

Author: acolomb

canopen/objectdictionary/eds.py

@@ -85,7 +85,8 @@ def import_eds(source, node_id):
                 pass
 
     if eds.has_section("DeviceComissioning"):
-        od.bitrate = int(eds.get("DeviceComissioning", "Baudrate")) * 1000
+        if val := eds.get("DeviceComissioning", "Baudrate", fallback=None):
+            od.bitrate = int(val) * 1000
 
         if node_id is None:
             if val := eds.get("DeviceComissioning", "NodeID", fallback=None):