#13337 - Fixed unable to process lab messages

The problem was cause by missing annotation on the ExternalMessage class.
Field CaseClassification was not annotated with String enum type.

- Added correct annotation to the CaseClassification field in the ExternalMessage class.

Author: raulbob

sormas-backend/src/main/java/de/symeda/sormas/backend/externalmessage/ExternalMessage.java

@@ -224,6 +224,8 @@ public void setCaseClassification(CaseClassification caseClassification) {
 		this.caseClassification = caseClassification;
 	}
 
+	@Enumerated(EnumType.STRING)
+	@Column
 	public CaseClassification getCaseClassification() {
 		return caseClassification;
 	}