@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 (data.exists("timestamp")) {
        const UniValue& timestamp = data["timestamp"];
        if (timestamp.isNum()) {
            return timestamp.get_int64();
        } else if (timestamp.isStr() && timestamp.get_str() == "now") {
            return now;
        }
        throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Expected number or \"now\" timestamp value for key. got type %s", uvTypeName(timestamp.type())));
    }
    throw JSONRPCError(RPC_TYPE_ERROR, "Missing required timestamp field for key");
}
UniValue importmulti(const JSONRPCRequest& mainRequest)
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(mainRequest);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, mainRequest.fHelp)) {
        return NullUniValue;
    }
    if (mainRequest.fHelp || mainRequest.params.size() < 1 || mainRequest.params.size() > 2)
        throw std::runtime_error(
            RPCHelpMan{"importmulti",