Fix to avoid RRC->X2AP ticking every msec when x2ap task is not enabled

-Since the aim of itti RRC_SUBFRAME_PROCESS message (MAC->RRC) is to trigger an itti X2AP_SUBFRAME_PROCESS message (RRC->X2AP), avoid creating
RRC_SUBFRAME_PROCESS message if x2ap task is not enabled. Not sure if this is the best solution. We could also avoid only sending the second itti X2AP_SUBFRAME_PROCESS message.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

@@ -58,6 +58,7 @@
 #include "intertask_interface.h"
 
 #include "executables/softmodem-common.h"
+#include "x2ap_eNB.h"
 
 const uint8_t slots_per_frame[5] = {10, 20, 40, 80, 160};
 uint16_t nr_pdcch_order_table[6] = { 31, 31, 511, 2047, 2047, 8191 };
@@ -445,6 +446,7 @@ void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
   if ((slot & ((1 << *scc->ssbSubcarrierSpacing) - 1)) == 0) {
     void nr_rlc_tick(int frame, int subframe);
     nr_rlc_tick(frame, slot >> *scc->ssbSubcarrierSpacing);
+    if (is_x2ap_enabled())
       nr_rrc_trigger(&ctxt, 0 /*CC_id*/, frame, slot >> *scc->ssbSubcarrierSpacing);
   }