fix: use the existing naming convention

Co-authored-by: Kevin Dougan SmileCDR <[email protected]>

Author: barabo

src/main/resources/application.yaml

@@ -116,7 +116,7 @@ hapi:
     #    allow_multiple_delete: true
     #    allow_override_default_search_params: true
     #    auto_create_placeholder_reference_targets: false
-    #    enable_mass_ingestion_mode: false
+    #    mass_ingestion_mode_enabled: false
     ### tells the server to automatically append the current version of the target resource to references at these paths
     #    auto_version_reference_at_paths: Device.patient, Device.location, Device.parent, DeviceMetric.parent, DeviceMetric.source, Observation.device, Observation.subject
     #    ips_enabled: false