@jonasschnelli wrote in #14979:
> #14573 broke < Qt5.6 compatibility due to calling the lambda version of `addAction` that was added in Qt5.6.

We currently [support](https://github.com/bitcoin/bitcoin/blob/master/doc/dependencies.md) QT >=5.2, but hardly anyone tests with that. If we make one of the Travis machines use it, we should have a better change of catching this.

See also discussion about minimum QT version in #13478 
"If you have the full public key, you should call importpubkey instead of this.\n"
            "\nNote: If you import a non-standard raw script in hex form, outputs sending to it will be treated\n"
            "as change, and not show up in many RPCs.\n",
                {
                    {"address", RPCArg::Type::STR,  false,  "", "The Bitcoin address (or hex-encoded script)"},
                    {"label", RPCArg::Type::STR,  true,  "\"\"", "An optional label"},
                    {"rescan", RPCArg::Type::BOOL,  true,  "true", "Rescan the wallet for transactions"},
                    {"p2sh", RPCArg::Type::BOOL,  true,  "false", "Add the P2SH version of the script as well"},
                },
                RPCResults{},
                RPCExamples{
            "\nImport an address with rescan\n"
            + HelpExampleCli("importaddress", "\"myaddress\"") +
            "\nImport using a label without rescan\n"
            + HelpExampleCli("importaddress", "\"myaddress\" \"testing\" false") +
            "\nAs a JSON-RPC call\n"
            + HelpExampleRpc("importaddress", "\"myaddress\", \"testing\", false")
                },
            }.ToString());
    std::string strLabel;
    if (!request.params[1].isNull())
        strLabel = request.params[1].get_str();
    
    bool fRescan = true;
    if (!request.params[2].isNull())
        fRescan = request.params[2].get_bool();
    if (fRescan && fPruneMode)
        throw JSONRPCError(RPC_WALLET_ERROR, "Rescan is disabled in pruned mode");
    WalletRescanReserver reserver(pwallet);
    if (fRescan && !reserver.reserve()) {