MT#62181 silence compiler warning

../hash_table.h:157:18: warning: ‘bool ht_map_bucket<Key, Value, ElmtCompare>::insert(const Key&, Value*) [with Key = bl_addr; Value = bl_entry; ElmtCompare = std::less<bl_addr>]’ was hidden [-Woverloaded-virtual=]
  157 |     virtual bool insert(const Key& k, Value* v) {
      |                  ^~~~~~
tr_blacklist.h:74:8: note:   by ‘bool blacklist_bucket::insert(const bl_addr&, uint64_t, const char*)’
   74 |   bool insert(const bl_addr& addr, uint64_t duration /* ms */,
      |        ^~~~~~

Change-Id: Ia8f81e2fa94755e230cd67c8eae95a2617cb028e

core/sip/tr_blacklist.h

@@ -70,6 +70,7 @@ public:
   : bl_bucket_base(id)
   {}
 
+  using ht_map_bucket<bl_addr, bl_entry>::insert;
   bool insert(const bl_addr& addr, uint64_t duration /* ms */,
 	      const char* reason);
   bool remove(const bl_addr& addr);