@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 
"\nImport addresses/scripts (with private or public keys, redeem script (P2SH)), optionally rescanning the blockchain from the earliest creation time of the imported scripts. Requires a new wallet backup.\n"
                "If an address/script is imported without all of the private keys required to spend from that address, it will be watchonly. The 'watchonly' option must be set to true in this case or a warning will be returned.\n"
                "Conversely, if all the private keys are provided and the address/script is spendable, the watchonly option must be set to false, or a warning will be returned.\n"
            "\nNote: This call can take over an hour to complete if rescan is true, during that time, other rpc calls\n"
            "may report that the imported keys, addresses or scripts exists but related transactions are still missing.\n",
                {
                    {"requests", RPCArg::Type::ARR,  false,  "", "Data to be imported",
                        {
                            {"", RPCArg::Type::OBJ,  false,  "", "",
                                {
                                    {"scriptPubKey", RPCArg::Type::STR,  false,  "", "Type of scriptPubKey (string for script, json for address)",
                                         "", {"\"<script>\" | { \"address\":\"<address>\" }", "string / json"}
                                    },
                                    {"timestamp", RPCArg::Type::NUM,  false,  "", "Creation time of the key in seconds since epoch (Jan 1 1970 GMT),\n"
        "                                                              or the string \"now\" to substitute the current synced blockchain time. The timestamp of the oldest\n"
        "                                                              key will determine how far back blockchain rescans need to begin for missing wallet transactions.\n"
        "                                                              \"now\" can be specified to bypass scanning, for keys which are known to never have been used, and\n"
        "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest key\n"
        "                                                              creation time of all keys being imported by the importmulti call will be scanned.",
                                         "", {"timestamp | \"now\"", "integer / string"}
                                    },
                                    {"redeemscript", RPCArg::Type::STR,  true,  "omitted", "Allowed only if the scriptPubKey is a P2SH or P2SH-P2WSH address/scriptPubKey"},
                                    {"witnessscript", RPCArg::Type::STR,  true,  "omitted", "Allowed only if the scriptPubKey is a P2SH-P2WSH or P2WSH address/scriptPubKey"},
                                    {"pubkeys", RPCArg::Type::ARR,  true,  "empty array", "Array of strings giving pubkeys to import. They must occur in P2PKH or P2WPKH scripts. They are not required when the private key is also provided (see the \"keys\" argument).",
                                        {
                                            {"pubKey", RPCArg::Type::STR,  false,  "", ""},
                                        }
                                    },
                                    {"keys", RPCArg::Type::ARR,  true,  "empty array", "Array of strings giving private keys to import. The corresponding public keys must occur in the output or redeemscript.",
                                        {