Convert Js5MasterIndex.Entry to a data class

Spotted by Desetude.

I think this was an accident, as the similar Js5Index.Entry class can't
be a data class (as it contains an array).

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

cache/src/main/kotlin/org/openrs2/cache/Js5MasterIndex.kt

@@ -3,29 +3,7 @@ package org.openrs2.cache
 import io.netty.buffer.ByteBuf
 
 public inline class Js5MasterIndex(public val entries: MutableList<Entry> = mutableListOf()) {
-    public class Entry(public var version: Int, public var checksum: Int) {
-        override fun equals(other: Any?): Boolean {
-            if (this === other) return true
-            if (javaClass != other?.javaClass) return false
-
-            other as Entry
-
-            if (version != other.version) return false
-            if (checksum != other.checksum) return false
-
-            return true
-        }
-
-        override fun hashCode(): Int {
-            var result = version
-            result = 31 * result + checksum
-            return result
-        }
-
-        override fun toString(): String {
-            return "Entry{version=$version, checksum=$checksum}"
-        }
-    }
+    public data class Entry(public var version: Int, public var checksum: Int)
 
     public fun write(buf: ByteBuf) {
         for (entry in entries) {