Fixing Docker entrypoint for storage node (#212)

cmd/piecestore-farmer/entrypoint

@@ -2,15 +2,9 @@
 set -euo pipefail
 
 # Create a new farmer, if the ID for an existing farmer isn't specified.
-if [ -z "${PSID}" ]; then
+if [[ -z $PSID ]]; then
 	mkdir -p "${PS_DIR}"
-	export PSID=$(./piecestore-farmer create \
-		--pieceStoreHost=${PUBLIC_IP} \
-		--pieceStorePort=${RPC_PORT} \
-		--kademliaPort=${KAD_PORT} \
-		--kademliaHost=${KAD_HOST} \
-		--kademliaListenPort=${KAD_LISTEN_PORT} \
-		--dir=${PS_DIR} | awk '/created/ { print $2 }')
+	export PSID=$(./piecestore-farmer create | awk '/created/ { print $2 }')
 	echo "Created farmer $PSID"
 fi
 exec ./piecestore-farmer start $PSID