pelican_open: don't raise IndexError on empty files
pelican_open: don't raise IndexError on empty files

If the file is empty, content[0] raises IndexError.

Rogdham/pelican,ehashman/pelican,zackw/pelican,Scheirle/pelican,avaris/pelican,lucasplus/pelican,iKevinY/pelican,Scheirle/pelican,farseerfc/pelican,iKevinY/pelican,ingwinlu/pelican,getpelican/pelican,talha131/pelican,Rogdham/pelican,lucasplus/pelican,farseerfc/pelican,zackw/pelican,ehashman/pelican,ehashman/pelican,Scheirle/pelican,lucasplus/pelican,talha131/pelican,douglaskastle/pelican,Rogdham/pelican,ingwinlu/pelican,douglaskastle/pelican,getpelican/pelican,avaris/pelican,zackw/pelican,douglaskastle/pelican