make password field disabled default to prevent misleading of autofill

[maidis]

submit privately checkbox not active in default behavior but sometimes password field fill by autofill and this misleads the user although the user thinks that paste is public, the paste is actualy private

const bool priv = params.value(QStringLiteral("private")) == QLatin1String("on") || !password.isEmpty();

these changes can help guide the user better:

• if submit privately not checked and no password: public
• if submit privately checked and no pasword: unlisted
• if submit privately checked and some password: private