JspServletWrapper.handleJspException can throws NullPointerException

[EricBlanquer]

jastow/src/main/java/org/apache/jasper/servlet/JspServletWrapper.java

Line 550 in efe20cd

StackTraceElement[] frames = realException.getStackTrace();

Hi,
"realException" can be null in case of "((ServletException) ex).getRootCause()" is null

[moulalis]

PR sent #63