clightning: don't cleanup socket on startup

This is now taken care of by clightning itself.

modules/clightning.nix

@@ -170,8 +170,6 @@ in {
       requires = [ "bitcoind.service" ];
       after = [ "bitcoind.service" ];
       preStart = ''
-        # The RPC socket has to be removed otherwise we might have stale sockets
-        rm -f ${cfg.networkDir}/lightning-rpc
         umask u=rw,g=r,o=
         {
           cat ${configFile}