add a note that QXmppTransferManager::sendFile requires a full JID
add a note that QXmppTransferManager::sendFile requires a full JID

ycsoft/qxmpp,olesalscheider/qxmpp,Kaffeine/qxmpp,kollix/qxmpp,pol51/QXMPP-CMake,Kaffeine/qxmpp,LightZam/qxmpp,Ilyatk/qxmpp,gamenet/qxmpp,kollix/qxmpp,pol51/QXMPP-CMake,Ilyatk/qxmpp,LightZam/qxmpp,gotomypc/qxmpp,olesalscheider/qxmpp,gotomypc/qxmpp,Ilyatk/qxmpp,olesalscheider/qxmpp,KangLin/qxmpp,cccco/qxmpp,Kaffeine/qxmpp,gotomypc/qxmpp,KangLin/qxmpp,gamenet/qxmpp,cccco/qxmpp,LightZam/qxmpp,KangLin/qxmpp,kollix/qxmpp,cccco/qxmpp,pol51/QXMPP-CMake,gamenet/qxmpp,ycsoft/qxmpp,ycsoft/qxmpp