fix ContentType JavaDoc

Author: winfriedgerlach

httpcore5/src/main/java/org/apache/hc/core5/http/ContentType.java

@@ -423,10 +423,8 @@ public static ContentType parse(final CharSequence s) throws UnsupportedCharsetE
      *
      * @param s text
      * @return content type {@code Content-Type} value or null.
-     * @throws UnsupportedCharsetException Thrown when the named charset is not available in
-     * this instance of the Java virtual machine
      */
-    public static ContentType parseLenient(final CharSequence s) throws UnsupportedCharsetException {
+    public static ContentType parseLenient(final CharSequence s) {
         return parse(s, false);
     }