Make sure to reload the file before reading it, it's updated in the background...

Make sure to reload the file before reading it, it's updated in the background by a SpecialMailCollectionsRequestJob
Fix signature of Q_PRIVATE_SLOT so slot is really called...

Saving as draft, sending, and other specialcollection-related things should now work after deleting an agent while kmail is running.
CCBUG: 237279

svn path=/trunk/KDE/kdepimlibs/; revision=1133929