javaunohelper: fix javadoc error: unknown tag: attention (Doxygen)

Change-Id: Idd1d92699cab0ccb26b95e9d5392c6fc7a8a2aa6
Reviewed-on: https://gerrit.libreoffice.org/11308Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

javaunohelper/com/sun/star/lib/uno/helper/Factory.java

@@ -29,8 +29,9 @@ import com.sun.star.uno.UnoRuntime;
 /** Factory helper class supporting com.sun.star.lang.XServiceInfo and
     com.sun.star.lang.XSingleComponentFactory.
 
-    @attention
-    This factory implementation does not support lang.XSingleServiceFactory.
+    <p>
+    Note: This factory implementation does not support lang.XSingleServiceFactory.
+    </p>
 */
 public class Factory
     extends ComponentBase