rpc: Fix implicit-integer-sign-change in verifychain

Author: MarcoFalke

src/rpc/blockchain.cpp

@@ -1417,7 +1417,7 @@ static RPCHelpMan verifychain()
                 },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
-    const int check_level(request.params[0].isNull() ? DEFAULT_CHECKLEVEL : request.params[0].get_int());
+    const int check_level{request.params[0].isNull() ? DEFAULT_CHECKLEVEL : request.params[0].get_int()};
     const int check_depth{request.params[1].isNull() ? DEFAULT_CHECKBLOCKS : request.params[1].get_int()};
 
     ChainstateManager& chainman = EnsureAnyChainman(request.context);

src/validation.h

@@ -90,7 +90,7 @@ static const int DEFAULT_STOPATHEIGHT = 0;
 /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of ActiveChain().Tip() will not be pruned. */
 static const unsigned int MIN_BLOCKS_TO_KEEP = 288;
 static const signed int DEFAULT_CHECKBLOCKS = 6;
-static const unsigned int DEFAULT_CHECKLEVEL = 3;
+static constexpr int DEFAULT_CHECKLEVEL{3};
 // Require that user allocate at least 550 MiB for block & undo files (blk???.dat and rev???.dat)
 // At 1MB per block, 288 blocks = 288MB.
 // Add 15% for Undo data = 331MB