Add missing variable declaration

impl/src/layer1/rx.c

@@ -158,6 +158,9 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 	float complex samples2dump2[sample_count];
 	size_t nsamples2dump2 = 0;
 
+	// cache configuration flags
+	bool is_central_node = options_is_flag_set(OPTIONS_FLAG_IS_CENTRAL_NODE);
+
 	// filter the input
 	float complex filtered_samples[sample_count];
 	firfilt_crcf_execute_block(rx->channel_filter, (float complex *)samples, sample_count, filtered_samples);