multiple legal notes are shown if project had multiple .class files opened in the editor

(cherry picked from commit 8a370d1d63173484f94fd9ad0bef9c45d377173f)

plugins/java-decompiler/plugin/src/org/jetbrains/java/decompiler/IdeaDecompiler.java

@@ -113,7 +113,9 @@ public class IdeaDecompiler extends ClassFileDecompilers.Light {
       ApplicationManager.getApplication().invokeLater(new Runnable() {
         @Override
         public void run() {
-          new LegalNoticeDialog(project, file).show();
+          if (!myLegalNoticeAccepted) {
+            new LegalNoticeDialog(project, file).show();
+          }
         }
       }, ModalityState.NON_MODAL);
     }