fix: avoid re-initializing g_txindex by checking first

Author: kwvg

src/test/util/setup_common.cpp

@@ -361,8 +361,10 @@ void TestChainSetup::mineBlocks(int num_blocks)
         m_coinbase_txns.push_back(b.vtx[0]);
     }
 
-    g_txindex = std::make_unique<TxIndex>(1 << 20, true);
-    assert(g_txindex->Start(m_node.chainman->ActiveChainstate()));
+    if (!g_txindex) {
+        g_txindex = std::make_unique<TxIndex>(1 << 20, true);
+        assert(g_txindex->Start(m_node.chainman->ActiveChainstate()));
+    }
 
     // Allow tx index to catch up with the block index.
     IndexWaitSynced(*g_txindex);