avoid swallowing causedBy exception in PlainBatchParameterProcessor

Signed-off-by: Lee Surprenant <lmsurpre@merative.com>

fhir-persistence-params/src/main/java/org/linuxforhealth/fhir/persistence/params/database/PlainBatchParameterProcessor.java

@@ -114,7 +114,7 @@ public void pushBatch() throws FHIRPersistenceException {
                 try {
                     dao.pushBatch();
                 } catch (SQLException x) {
-                    throw new FHIRPersistenceException("pushBatch failed for '" + resourceType + "'");
+                    throw new FHIRPersistenceException("pushBatch failed for '" + resourceType + "'", x);
                 }
             }