Fix savegame not loading and improve build

start.sh

@@ -1,9 +1,12 @@
 #!/bin/sh
-SAVE_FILE="/root/.openttd/save/autosave/latest.sav"
+SAVE_DIR="/root/.openttd/save"
+LATEST_SAVE=$(ls -rt ${SAVE_DIR}/autosave/ | tail -n1)
+ABSOLUTE_SAVE="$SAVE_DIR/autosave/$LATEST_SAVE"
 
-if [ -f "$SAVE_FILE" ]; then
-    echo "Loading savegame: $SAVE_FILE"
-    exec /openttd/openttd -D -g autosave/latest.sav
+
+if [ -f "$ABSOLUTE_SAVE" ]; then
+    echo "Loading savegame: $LATEST_SAVE"
+    exec /openttd/openttd -D -g $ABSOLUTE_SAVE
 else
     echo "No savegame found. Starting new game."
     exec /openttd/openttd -D