refactor: Use C++11 range based for loops to simplify rpc code

src/rpc/mining.cpp

@@ -1200,7 +1200,7 @@ static const CRPCCommand commands[] =
     { "hidden",             "estimaterawfee",         &estimaterawfee,         {"conf_target", "threshold"} },
 };
 // clang-format on
-
-    for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++)
-        t.appendCommand(commands[vcidx].name, &commands[vcidx]);
+    for (const auto& c : commands) {
+        t.appendCommand(c.name, &c);
+    }
 }