make time column configurable

Adding the header of the time column to the
CsvReaderSettings. This is necessary to parse
arbitrary CSV files.

pdb-ui/src/main/java/org/lucares/pdbui/IngestionHandler.java

@@ -66,7 +66,7 @@ public final class IngestionHandler implements Callable<Void> {
         } else {
             in.reset();
             final CsvToEntryTransformer csvTransformer = new CsvToEntryTransformer(queue,
-                    CsvReaderSettings.create(','));
+                    CsvReaderSettings.create("@timestamp", ','));
             csvTransformer.readCSV(in);
         }
     }