CPaster: Let cpaster finish on console

If cpaster is used from command line and KDE
paster is used as protocol we have no appropriate
way to specify the credentials yet.
Emit a signal to avoid letting the application
wait infinitely.

Change-Id: I7895d5211f1573fae0f69d2ea76532dec53b8d98
Reviewed-by: Filipe Azevedo <filipe.azevedo@kdab.com>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cpaster/kdepasteprotocol.cpp

@@ -302,6 +302,7 @@ void KdePasteProtocol::paste(const QString &text, Protocol::ContentType ct, int
     const QString user;
     const QString passwd;
     qDebug() << "KDE needs credentials for pasting";
+    emit pasteDone(QString());
     return;
 #endif
     // store input data as members to be able to use them after the authentication succeeded