#41 removed duplicated extension registration

Author: raydac

jbbp-plugins/jbbp-gradle/src/main/java/com/igormaznitsa/jbbp/plugin/gradle/JBBPPlugin.java

@@ -8,8 +8,6 @@ public class JBBPPlugin implements Plugin<Project> {
 
   @Override
   public void apply(@Nonnull final Project project) {
-    project.getExtensions().create(JBBPExtension.EXT_NAME, JBBPExtension.class, project);
-
     JBBPExtension extension = project.getExtensions()
         .create(JBBPExtension.class, JBBPExtension.EXT_NAME, JBBPExtension.class, project);
     project.getTasks().register("jbbpGenerate", JBBPGenerateTask.class, task -> {