gstlal_snax_dag_online: add a --features-path for pointing to features directory explicitly

gstlal-burst/bin/gstlal_snax_dag_online

@@ -173,6 +173,7 @@ def parse_command_line():
 	group = optparse.OptionGroup(parser, "Synchronizer/File Sink Options", "Adjust parameters used for synchronization and dumping of features to disk.")
 	parser.add_option("--tag", metavar = "string", default = "test", help = "Sets the name of the tag used. Default = 'test'")
 	parser.add_option("--no-drop", default=False, action="store_true", help = "If set, do not drop incoming features based on the latency timeout. Default = False.")
+	parser.add_option("--features-path", metavar = "path", default = ".", help = "Write features to this path. Default = .")
 	parser.add_option("--processing-cadence", type = "float", default = 0.1, help = "Rate at which the streaming jobs acquire and processes data. Default = 0.1 seconds.")
 	parser.add_option("--request-timeout", type = "float", default = 0.2, help = "Timeout for requesting messages from a topic. Default = 0.2 seconds.")
 	parser.add_option("--latency-timeout", type = "float", default = 5, help = "Maximum time before incoming data is dropped for a given timestamp. Default = 5 seconds.")
@@ -279,6 +280,7 @@ if options.save_format == 'kafka':
 	hdf5_sink_options = {
 		"instrument": ifo,
 		"channel-list": options.channel_list,
+		"features-path": options.features_path,
 		"waveform": options.waveform,
 		"sample-rate": options.sample_rate,
 		"write-cadence": options.cadence,