smb: map ECONNABORTED to ERR_CONNECTION_BROKEN
seems the most reasonable candidate given the pretty strings in
KIO::buildErrorString and the detailed causes in the detail function.
this does not really improve the error message, but should dolphin
ever learn to pick up details from detailedErrorStrings it would make
ECONNABORTED can mean any number of things, so I guess a signle line
error will always be incredibly vague.
Test Plan: hoping for the best!
Reviewed By: ngraham
Subscribers: kde-frameworks-devel, kfm-devel
Differential Revision: https://phabricator.kde.org/D27377