fix: random seed not loading on reload of rustserver

lgsm/config-default/config-lgsm/rustserver/_default.cfg

@@ -20,7 +20,7 @@ servername="Rust"
 gamemode="vanilla" # Values: vanilla, softcore ( Doc: https://wiki.facepunch.com/rust/server-gamemodes )
 serverlevel="Procedural Map" # Values: Procedural Map, Barren, HapisIsland, SavasIsland
 customlevelurl="" # Custom level url. +server.levelurl \"${customlevelurl}\"
-seed="" # range: 1-2147483647, used to reproduce a procedural map.
+seed="$(cat "${datadir}/${selfname}-seed.txt")" # range: 1-2147483647, used to reproduce a procedural map.
 salt="" # range: unknown, used to recover a known setting from an existing map.
 maxplayers="50"
 worldsize="3000" # default: 3000, range: 1000-6000, map size in meters.