Fix weight size issue in fc template

aidge_export_cpp/templates/configuration/fullyconnected_config.jinja

@@ -13,7 +13,7 @@
 static const {{ rescaling }} {{ name|upper }}_RESCALING = {};
 
 {#- Calculate sizes #}
-{%- set weights_size = output_dims[0] * input_dims[0] %}
+{%- set weights_size = output_dims[0] * input_dims[0] * input_dims[1] * input_dims[2] %}
 #define {{ name|upper }}_WEIGHTS_SIZE {{ weights_size }}
 #define {{ name|upper }}_BIASES_SIZE {{ output_dims[0] }}