It's not a good idea to use your owner key anywhere, unless you need to. The active key should be used for anything else if its required. If you verify it's really Steemconnect, the active key should be used if you have it. A lot of people will use their master password but it's pretty insecure because that includes the owner key.

Only the owner key can change the owner key, so if the password were compromised, your account is essentially owned by someone else. This makes getting your account back harder and not guaranteed, as you have to rely on your account's recovery account. Which will be @steem, owned by Steemit, if you used the Steemit faucet to create your account).