Fix build by restoring onIndexesUpdated override

Author: facchinm

app/src/cc/arduino/contributions/libraries/ui/LibraryManagerUI.java

@@ -200,7 +200,7 @@ protected void onUpdatePressed() {
       try {
         setProgressVisible(true, "");
         installer.updateIndex(this::setProgress);
-        //onIndexesUpdated();
+        onIndexesUpdated();
       } catch (Exception e) {
         throw new RuntimeException(e);
       } finally {
@@ -223,6 +223,7 @@ public void onInstallPressed(final ContributedLibrary lib, final Optional<Contri
           contribTable.getCellEditor().stopCellEditing();
         }
         ((LibrariesIndexTableModel) contribModel).update();
+        onIndexesUpdated();
       } catch (Exception e) {
         throw new RuntimeException(e);
       } finally {
@@ -254,6 +255,7 @@ public void onRemovePressed(final ContributedLibrary lib) {
           contribTable.getCellEditor().stopCellEditing();
         }
         ((LibrariesIndexTableModel) contribModel).update();
+        onIndexesUpdated();
       } catch (Exception e) {
         throw new RuntimeException(e);
       } finally {
@@ -264,4 +266,8 @@ public void onRemovePressed(final ContributedLibrary lib) {
     installerThread.setUncaughtExceptionHandler(new InstallerJDialogUncaughtExceptionHandler(this, noConnectionErrorMessage));
     installerThread.start();
   }
-}
+
+  protected void onIndexesUpdated() throws Exception {
+    // Empty
+  }
+}