Add back Third-party Libraries plugin center. (#1331)

diff --git a/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/Bundle.properties b/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/Bundle.properties
index c7dec18..024eecc 100644
--- a/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/Bundle.properties
+++ b/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/Bundle.properties
@@ -33,3 +33,7 @@
 URL_PluginPortal=https://netbeans.apache.org/nb/plugins/11.1/catalog.xml.gz
 #NOI18N
 URL_82PluginPortal=http://updates.netbeans.org/netbeans/updates/8.2/uc/final/distribution/catalog.xml.gz
+
+3rdparty=Third Party Libraries
+#NOI18N
+URL_3rdparty=nbresloc:/org/netbeans/modules/updatecenters/resources/3rdparty-catalog.xml
diff --git a/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/mf-layer.xml b/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/mf-layer.xml
index fc7cc33..de190a3 100644
--- a/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/mf-layer.xml
+++ b/nb/updatecenters/src/org/netbeans/modules/updatecenters/resources/mf-layer.xml
@@ -55,6 +55,16 @@
           <attr name="instanceCreate" methodvalue="org.netbeans.modules.autoupdate.updateprovider.AutoupdateCatalogFactory.createUpdateProvider"/>
       </file>
 
+      <file name="3rdparty.instance">
+          <attr name="displayName" bundlevalue="org.netbeans.modules.updatecenters.resources.Bundle#3rdparty"/>
+          <attr name="iconBase" stringvalue="org/netbeans/modules/updatecenters/resources/updateAction.gif"/>
+          <attr name="url" bundlevalue="org.netbeans.modules.updatecenters.resources.Bundle#URL_3rdparty"/>
+          <attr name="category" stringvalue="STANDARD"/>
+          <attr name="enabled" boolvalue="true"/>
+          <attr name="instanceOf" stringvalue="org.netbeans.spi.autoupdate.UpdateProvider"/>
+          <attr name="instanceCreate" methodvalue="org.netbeans.modules.autoupdate.updateprovider.AutoupdateCatalogFactory.createUpdateProvider"/>
+      </file>
+
    </folder>
     
   </folder> <!-- Services -->