Merge branch 'fix_nssai_sd' into 'develop'

Do not include SD (NSSAI) with value 0

See merge request oai/cn5g/oai-cn5g-smf!63

src/nas/ies/SNSSAI.c

@@ -44,7 +44,8 @@ int encode_snssai(SNSSAI snssai, uint8_t iei, uint8_t* buffer, uint32_t len) {
   }
 
   ielen = snssai.len;
-  //  ielen = 1;
+
+  if (snssai.sd == 0) ielen = 1;  // Don't include SD if it = 0
 
   *(buffer + encoded) = ielen;
   encoded++;