[qmf] Change IMAP4 default for auto download small attachments.

This commit turns off auto download of small attachments. Downloading small attachments without user permission is not a
desired behavior, some emails contain logs or small images that will be always download without user permission in this case.
upstream commit: https://qt.gitorious.org/qt-labs/messagingframework/commit/a6edd8df6fbaf6cf1daf0f1eb448b0905a619d5c

qmf/src/plugins/messageservices/imap/imapconfiguration.cpp

@@ -90,7 +90,7 @@ bool ImapConfiguration::canDeleteMail() const
 
 bool ImapConfiguration::downloadAttachments() const
 {
-    return (value("downloadAttachments", "1").toInt() != 0);
+    return (value("downloadAttachments", "0").toInt() != 0);
 }
 
 bool ImapConfiguration::isAutoDownload() const