TRUNK-2224 Show appropriate notification message when void reason is empty when voiding a patient

Repeating the comment put in the previous pr)
@dkayiwa
yaa true that but the point I am trying to make is.
When one clicks on "Delete" button the block containing the message:
action.equals(msa.getMessage("Patient.delete")) gets triggered and we can find out whether the "delete reason" provided by the user is empty or not,
by using the command, StringUtils.isNotBlank(patient.getVoidReason())
I have thoroughly tested this.
P.S. Talking about the version openmrs 1.11