Hello, I am truly sorry for replying to you so late.  
You were right to contact me because it turned out to be a mistake on my part that happened when I was not yet fully familiar with using OSM.  
I hadn't even noticed this error, even though I am active in this area. I thank you for contacting me and seeing a possible mistake on my part, and of course, I have put the node back in its place.  
Next time, I will be more careful with my edits and with messages...  
Finally, a segment of this line has been buried; it seems to me that it is not the one I mistakenly modified but the other one near the hamlet of 'Chaillargues' (sorry, it has no reference). I would need to research better to get more information on this. Thank you, and it is a pleasure if you want to contact me again.