Fix Checkstyle error

proxy/src/main/java/com/velocitypowered/proxy/connection/MinecraftConnection.java

@@ -223,9 +223,9 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
    */
   public void closeWith(Object msg) {
     if (channel.isActive()) {
-      boolean is1_7 = this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) < 0
+      boolean is17 = this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) < 0
           && this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_7_2) >= 0;
-      if (is1_7) {
+      if (is17) {
         channel.eventLoop().execute(() -> {
           // 1.7.x versions have a race condition with switching protocol states, so just explicitly
           // close the connection after a short while.