EXPloration: error when no worldborder exists
This is low priority since it doesn't effect production ever, since a worldborder always exists in production
```
java.lang.IllegalArgumentException: Cannot get random in empty range: 25147282..10000
at KotlinPluginStdLoader_deploy.jar//kotlin.random.RandomKt.nextInt(Random.kt:350) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.EXPloration.findSuitableRelicLocation(EXPloration.kt:154) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.RelicData$Companion.generateRandom(RelicData.kt:16) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.EXPloration.getOrCreateSoughtRelic(EXPloration.kt:106) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.EXPloration.getOrCreateSoughtRelic$default(EXPloration.kt:63) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.listeners.RelicDigListener.checkForCompassRelics(RelicDigListener.kt:96) ~[?:?]
at EXPloration-release.jar//plus.civ.exploration.listeners.RelicDigListener.onShovelLeftClick(RelicDigListener.kt:28) ~[?:?]
```
issue