Make obiconsensus using the count of the sequences

Former-commit-id: 7fc5292aeb225843a86cd85591a5405e35125e3d

pkg/obiformats/options.go

@@ -64,7 +64,7 @@ func MakeOptions(setters []WithOption) Options {
 		csv_keys:              make([]string, 0),
 		csv_auto:              false,
 		paired_filename:       "",
-		source:                "",
+		source:                "unknown",
 		with_feature_table:    false,
 	}