Make sure an IOException is always passed through as MessagingException
Make sure an IOException is always passed through as MessagingException

This is important for the code handling pending actions in
MessagingController. If a non-permantent MessagingException is
encountered, the pending action is retried later.

Fixes issue 3696
sanderbaas/k-9,XiveZ/k-9,439teamwork/k-9,sanderbaas/k-9,dpereira411/k-9,gaionim/k-9,GuillaumeSmaha/k-9,bashrc/k-9,leixinstar/k-9,tonytamsf/k-9,XiveZ/k-9,k9mail/k-9,gilbertw1/k-9,WenduanMou1/k-9,icedman21/k-9,farmboy0/k-9,imaeses/k-9,cooperpellaton/k-9,philipwhiuk/k-9,Valodim/k-9,dhootha/k-9,thuanpq/k-9,huhu/k-9,bashrc/k-9,sonork/k-9,huhu/k-9,farmboy0/k-9,sebkur/k-9,leixinstar/k-9,gnebsy/k-9,tsunli/k-9,imaeses/k-9,rollbrettler/k-9,cooperpellaton/k-9,suzp1984/k-9,msdgwzhy6/k-9,k9mail/k-9,herpiko/k-9,konfer/k-9,CodingRmy/k-9,deepworks/k-9,denim2x/k-9,nilsbraden/k-9,GuillaumeSmaha/k-9,rishabhbitsg/k-9,sebkur/k-9,gnebsy/k-9,icedman21/k-9,vt0r/k-9,mawiegand/k-9,roscrazy/k-9,jca02266/k-9,dpereira411/k-9,KitAway/k-9,GuillaumeSmaha/k-9,crr0004/k-9,suzp1984/k-9,farmboy0/k-9,sedrubal/k-9,thuanpq/k-9,jca02266/k-9,gilbertw1/k-9,cketti/k-9,WenduanMou1/k-9,dhootha/k-9,sonork/k-9,439teamwork/k-9,torte71/k-9,jca02266/k-9,cooperpellaton/k-9,mawiegand/k-9,herpiko/k-9,tsunli/k-9,thuanpq/k-9,moparisthebest/k-9,huhu/k-9,dhootha/k-9,vt0r/k-9,suzp1984/k-9,WenduanMou1/k-9,philipwhiuk/q-mail,vasyl-khomko/k-9,msdgwzhy6/k-9,dgger/k-9,philipwhiuk/k-9,gnebsy/k-9,moparisthebest/k-9,deepworks/k-9,github201407/k-9,tsunli/k-9,dgger/k-9,KitAway/k-9,gaionim/k-9,mawiegand/k-9,torte71/k-9,denim2x/k-9,cketti/k-9,msdgwzhy6/k-9,ndew623/k-9,cliniome/pki,indus1/k-9,cketti/k-9,vasyl-khomko/k-9,Eagles2F/k-9,rollbrettler/k-9,crr0004/k-9,github201407/k-9,k9mail/k-9,sedrubal/k-9,konfer/k-9,leixinstar/k-9,Eagles2F/k-9,jberkel/k-9,philipwhiuk/q-mail,torte71/k-9,gaionim/k-9,rishabhbitsg/k-9,XiveZ/k-9,G00fY2/k-9_material_design,cliniome/pki,dpereira411/k-9,tonytamsf/k-9,rtreffer/openpgp-k-9,bashrc/k-9,herpiko/k-9,rollbrettler/k-9,moparisthebest/k-9,nilsbraden/k-9,roscrazy/k-9,rtreffer/openpgp-k-9,cketti/k-9,sebkur/k-9,crr0004/k-9,Eagles2F/k-9,deepworks/k-9,gilbertw1/k-9,vasyl-khomko/k-9,KitAway/k-9,439teamwork/k-9,cliniome/pki,dgger/k-9,vatsalsura/k-9,github201407/k-9,nilsbraden/k-9,ndew623/k-9,vatsalsura/k-9,philipwhiuk/q-mail,jberkel/k-9,imaeses/k-9,sanderbaas/k-9,icedman21/k-9,sonork/k-9,denim2x/k-9,ndew623/k-9,G00fY2/k-9_material_design,tonytamsf/k-9,konfer/k-9,CodingRmy/k-9,indus1/k-9