Fix block height refresh estimation

Author: hayzamjs

src/wallet/wallet2.cpp

@@ -10152,11 +10152,11 @@ uint64_t wallet2::get_daemon_blockchain_target_height(string &err)
 uint64_t wallet2::get_approximate_blockchain_height() const
 {
   // time of v2 fork
-  const time_t fork_time = m_nettype == TESTNET ? 1448285909 : m_nettype == STAGENET ? 1520937818 : 1458748658;
+  const time_t fork_time = m_nettype == TESTNET ? 1448285909 : m_nettype == STAGENET ? 1520937818 : 1520584977;
   // v2 fork block
-  const uint64_t fork_block = m_nettype == TESTNET ? 624634 : m_nettype == STAGENET ? 32000 : 1009827;
+  const uint64_t fork_block = m_nettype == TESTNET ? 624634 : m_nettype == STAGENET ? 32000 : 67500;
   // avg seconds per block
-  const int seconds_per_block = DIFFICULTY_TARGET_V2;
+  const int seconds_per_block = DIFFICULTY_TARGET_V5;
   // Calculated blockchain height
   uint64_t approx_blockchain_height = fork_block + (time(NULL) - fork_time)/seconds_per_block;
   // testnet got some huge rollbacks, so the estimation is way off