Ensure master index format is set to VERSIONED

This ensures the server sends a master index compatible with the client
even if all the indexes in the cache use the original Js5Index format.

Signed-off-by: Graham <gpe@openrs2.org>

cache/src/main/kotlin/org/openrs2/cache/Js5MasterIndexProvider.kt

@@ -7,6 +7,8 @@ public class Js5MasterIndexProvider @Inject constructor(
     private val store: Store
 ) : Provider<Js5MasterIndex> {
     override fun get(): Js5MasterIndex {
-        return Js5MasterIndex.create(store)
+        val masterIndex = Js5MasterIndex.create(store)
+        masterIndex.format = MasterIndexFormat.VERSIONED
+        return masterIndex
     }
 }