Restrict supported HTTP methods

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

game/src/main/kotlin/org/openrs2/game/net/http/HttpChannelHandler.kt

@@ -4,6 +4,7 @@ import io.netty.channel.ChannelHandler
 import io.netty.channel.ChannelHandlerContext
 import io.netty.channel.SimpleChannelInboundHandler
 import io.netty.handler.codec.http.HttpHeaderValues
+import io.netty.handler.codec.http.HttpMethod
 import io.netty.handler.codec.http.HttpRequest
 import io.netty.handler.codec.http.HttpResponseStatus
 import io.netty.handler.timeout.IdleStateEvent
@@ -28,6 +29,11 @@ public class HttpChannelHandler @Inject constructor(
             return
         }
 
+        if (msg.method() != HttpMethod.HEAD && msg.method() != HttpMethod.GET) {
+            Http.writeResponse(ctx, msg, HttpResponseStatus.METHOD_NOT_ALLOWED)
+            return
+        }
+
         fileProvider.get(uri.substring(1)).use { file ->
             if (file == null) {
                 Http.writeResponse(ctx, msg, HttpResponseStatus.NOT_FOUND)