Use exec to start IPFS daemon

This incorporates feedback from @RX14 in #1685 and might fix #1537 as the ipfs daemon would get the stop signal from the docker daemon... Maybe that way it stops in a cleaner manner...

License: MIT
Signed-off-by: Knut Ahlers <knut@ahlers.me>

bin/container_daemon

@@ -18,4 +18,4 @@ else
   ipfs config Addresses.Gateway /ip4/0.0.0.0/tcp/8080
 fi
 
-ipfs daemon
+exec ipfs daemon