dronedge.h: stop hardcoding variables number

Define the number of OPC-UA variables of each entity (drone or subscriber) in a
global value.

include/dronedge.h

@@ -5,8 +5,8 @@
 #include "autopilot_wrapper.h"
 #include "pubsub.h"
 
-#define MAX_VARIABLE_NB 3
-
+#define DRONE_VARIABLE_NB 3
+#define SUBSCRIBER_VARIABLE_NB 1
 struct messageNode {
   char *message;
   struct messageNode *next;
@@ -66,7 +66,7 @@ VariableData droneVariableArray[] = {
 };
 
 VariableStruct droneVariables = {
-    .nbVariable = 3,
+    .nbVariable = DRONE_VARIABLE_NB,
     .variableArray = droneVariableArray,
 };
 
@@ -85,7 +85,7 @@ VariableData subscriberVariableArray[] = {
 };
 
 VariableStruct subscriberVariables = {
-    .nbVariable = 1,
+    .nbVariable = SUBSCRIBER_VARIABLE_NB,
     .variableArray = subscriberVariableArray,
 };
 

qjs_wrapper.c

+#include <math.h>
 #include <pthread.h>
 #include "dronedge.h"
 
@@ -516,7 +517,8 @@ static JSValue js_run_pubsub(JSContext *ctx, JSValueConst this_val,
 
     pubsubExited = false;
     res = runPubsub(logger, &transportProfile, &networkAddressUrl, variables,
-                    id, instanceArray, nbPeer, MAX_VARIABLE_NB, interval,
+                    id, instanceArray, nbPeer,
+                    fmax(DRONE_VARIABLE_NB, SUBSCRIBER_VARIABLE_NB), interval,
                     get_drone_id, pubsub_get_value, pubsub_update_variables,
                     &pubsubShouldRun);
     pubsubExited = true;