use the old id generator as it's the one we were using before dropwizard

src/main/java/com/commafeed/CommaFeedConfiguration.java

@@ -35,7 +35,7 @@ public class CommaFeedConfiguration extends Configuration {
 	@Valid
 	@NotNull
 	@JsonProperty("database")
-	private DataSourceFactory database = new DataSourceFactory();
+	private DataSourceFactory dataSourceFactory = new DataSourceFactory();
 
 	@Valid
 	@NotNull