Remove deprecated XmlStringBuilder.rightAngelBracket()

This method was marked deprecated with bbf89c65b ("Fix typo in
XmlStringBuilder, it's not an Angel"). Now it is time to remove it.

smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java

@@ -245,17 +245,6 @@ public class XmlStringBuilder implements Appendable, CharSequence, Element {
         return this;
     }
 
-    /**
-     * Add a right angle bracket '>'.
-     *
-     * @return a reference to this object
-     * @deprecated use {@link #rightAngleBracket()} instead
-     */
-    @Deprecated
-    public XmlStringBuilder rightAngelBracket() {
-        return rightAngleBracket();
-    }
-
     /**
      * Does nothing if value is null.
      *