KSMTP: Fix sending emails where a line starts with a dot
Summary:
My previous fix was incomplete because it only considered lines
with a single dot, and not the case where two such lines followed each
other.
BUG: 392049
FIXED-IN: 18.04
Test Plan: Updated unittest.
Reviewers: dvratil, mlaurent
Subscribers: KDE PIM
Differential Revision: https://phabricator.kde.org/D12434