fix rollback of edge update
fix rollback of edge update

The rollback of edge marker modification used a wrong marker size and thus uninitialised memory.
Achim found this

razvanphp/arangodb,razvanphp/arangodb,mujiansu/arangodb,razvanphp/arangodb,morsdatum/ArangoDB,abaditsegay/arangodb,nvoron23/arangodb,kkdd/arangodb,mujiansu/arangodb,nekulin/arangodb,kkdd/arangodb,kkdd/arangodb,morsdatum/ArangoDB,aurelijusb/arangodb,aurelijusb/arangodb,kkdd/arangodb,mujiansu/arangodb,aurelijusb/arangodb,aurelijusb/arangodb,pekeler/arangodb,nekulin/arangodb,morsdatum/ArangoDB,abaditsegay/arangodb,nvoron23/arangodb,pekeler/arangodb,mujiansu/arangodb,nekulin/arangodb,nvoron23/arangodb,aurelijusb/arangodb,morsdatum/ArangoDB,kkdd/arangodb,mujiansu/arangodb,nvoron23/arangodb,abaditsegay/arangodb,abaditsegay/arangodb,razvanphp/arangodb,abaditsegay/arangodb,abaditsegay/arangodb,razvanphp/arangodb,nvoron23/arangodb,mujiansu/arangodb,aurelijusb/arangodb,nekulin/arangodb,mujiansu/arangodb,kkdd/arangodb,aurelijusb/arangodb,mujiansu/arangodb,razvanphp/arangodb,abaditsegay/arangodb,razvanphp/arangodb,nekulin/arangodb,nvoron23/arangodb,pekeler/arangodb,razvanphp/arangodb,pekeler/arangodb,nekulin/arangodb,morsdatum/ArangoDB,pekeler/arangodb,morsdatum/ArangoDB,abaditsegay/arangodb,morsdatum/ArangoDB,kkdd/arangodb,razvanphp/arangodb,abaditsegay/arangodb,mujiansu/arangodb,morsdatum/ArangoDB,pekeler/arangodb,nekulin/arangodb,nvoron23/arangodb,nekulin/arangodb,kkdd/arangodb,nvoron23/arangodb,aurelijusb/arangodb,mujiansu/arangodb,aurelijusb/arangodb,aurelijusb/arangodb,pekeler/arangodb,morsdatum/ArangoDB,nekulin/arangodb,razvanphp/arangodb,kkdd/arangodb,abaditsegay/arangodb,nekulin/arangodb,pekeler/arangodb,morsdatum/ArangoDB,nvoron23/arangodb,kkdd/arangodb,pekeler/arangodb,nvoron23/arangodb,pekeler/arangodb