Fixes: Display manual case classification.

Summary:
Displaying the manual classification, which has configured in disease level
Changes:
Verifying the caseClassificationMode, if it's DISABLED, does nothing.
For AUTOMATIC, display the automatic case classification in the table.
For MANUAL, display the plain text box with the configured details.

Author: KarnaiahPesula

sormas-backend/src/main/java/de/symeda/sormas/backend/disease/DiseaseConfigurationFacadeEjb.java

@@ -444,7 +444,7 @@ public int getMinIncubationPeriod(Disease disease) {
 	}
 
 	public String getCaseDefinitionText(Disease disease) {
-		return service.getDiseaseConfiguration(disease).getCaseDefinitionText();
+		return service.getDiseaseConfiguration(disease) == null ? null : service.getDiseaseConfiguration(disease).getCaseDefinitionText();
 	}
 
 	@Override