This came up in a recent episode of the Great war. Indy asked if there is any proof for it and I'm also curious about it.
Considering that the French had no aircraft really capable of bombing, and certainly not with that range, no. The Germans made it up deliberately as a justification of their invasion of France, Belgium and Luxembourg. Similarly, they accused the Belgians of having allowed the French to send officers across their borders in the direction of Germany, despite the fact that there were no French units anywhere near the Belgian border.