Fix for required chainId check (#96)

Signed-off-by: Fabio Di Fabio <[email protected]>

Author: fab-10

sequencer/src/main/java/net/consensys/linea/AbstractLineaRequiredPlugin.java

@@ -64,8 +64,8 @@ public void register(final BesuContext context) {
   public abstract void doRegister(final BesuContext context);
 
   @Override
-  public void beforeExternalServices() {
-    super.beforeExternalServices();
+  public void start() {
+    super.start();
 
     blockchainService
         .getChainId()