Use syncthing 0.14.39

Dockerfile

@@ -28,7 +28,7 @@ RUN ./configure \
     --build=cloudron-river
 RUN make install
 
-ENV VERSION 0.14.38
+ENV VERSION 0.14.39
 
 RUN mkdir -p /app/code \
     && wget https://github.com/syncthing/syncthing/releases/download/v${VERSION}/syncthing-linux-amd64-v${VERSION}.tar.gz -O - \