[TASK] Add additional safeguard for corrupt user sessions
[TASK] Add additional safeguard for corrupt user sessions

This adds an additional check into Context->getPartyByType() to avoid
"called member function on a non-object" errors if a user seems to be
authenticated but, for some reason, the token could not provide the
respective account.

Change-Id: I5246fe5a0375f4378fe4a1bbd9e0f2b0283746c8
Releases: master
Original-Commit-Hash: b8cec90f5eb2849459c65f037e56b1b652a1c3bb

robertlemke/flow-development-collection,neos/flow-development-collection,fcool/flow-development-collection,kitsunet/flow-development-collection,aertmann/flow-development-collection,fcool/flow-development-collection,gerhard-boden/flow-development-collection,albe/flow-development-collection,daniellienert/flow-development-collection,neos/flow-development-collection,albe/flow-development-collection,albe/flow-development-collection,dfeyer/flow-development-collection,neos/flow-development-collection,dfeyer/flow-development-collection,robertlemke/flow-development-collection,kdambekalns/flow-development-collection,dlubitz/flow-development-collection,chewbakartik/flow-development-collection,neos/flow-development-collection,fcool/flow-development-collection,kdambekalns/flow-development-collection,gerhard-boden/flow-development-collection,mkeitsch/flow-development-collection,dlubitz/flow-development-collection,aertmann/flow-development-collection,bwaidelich/flow-development-collection,dfeyer/flow-development-collection,kdambekalns/flow-development-collection,mkeitsch/flow-development-collection,kdambekalns/flow-development-collection,daniellienert/flow-development-collection,robertlemke/flow-development-collection,gerhard-boden/flow-development-collection,bwaidelich/flow-development-collection,bwaidelich/flow-development-collection,chewbakartik/flow-development-collection,kitsunet/flow-development-collection,mkeitsch/flow-development-collection,fcool/flow-development-collection,aertmann/flow-development-collection,dlubitz/flow-development-collection,daniellienert/flow-development-collection,dfeyer/flow-development-collection,kitsunet/flow-development-collection,robertlemke/flow-development-collection,chewbakartik/flow-development-collection