Handle empty indices case
Handle empty indices case

This fixes Nemesis output when we have a processor that doesn't have
any indices here.

libMesh/libmesh,dschwen/libmesh,giorgiobornia/libmesh,hrittich/libmesh,dschwen/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,pbauman/libmesh,dschwen/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,giorgiobornia/libmesh,libMesh/libmesh,BalticPinguin/libmesh,pbauman/libmesh,roystgnr/libmesh,giorgiobornia/libmesh,BalticPinguin/libmesh,pbauman/libmesh,pbauman/libmesh,dschwen/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,libMesh/libmesh,BalticPinguin/libmesh,dschwen/libmesh,pbauman/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,roystgnr/libmesh,capitalaslash/libmesh,hrittich/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,roystgnr/libmesh,libMesh/libmesh,hrittich/libmesh,90jrong/libmesh,roystgnr/libmesh,capitalaslash/libmesh,hrittich/libmesh,capitalaslash/libmesh,dschwen/libmesh,pbauman/libmesh,dschwen/libmesh,jwpeterson/libmesh,90jrong/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,roystgnr/libmesh,dschwen/libmesh,hrittich/libmesh,libMesh/libmesh,90jrong/libmesh,hrittich/libmesh,90jrong/libmesh,pbauman/libmesh,hrittich/libmesh,pbauman/libmesh,jwpeterson/libmesh,roystgnr/libmesh,libMesh/libmesh,libMesh/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,hrittich/libmesh,jwpeterson/libmesh,hrittich/libmesh,BalticPinguin/libmesh,90jrong/libmesh,90jrong/libmesh,90jrong/libmesh,roystgnr/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,BalticPinguin/libmesh,90jrong/libmesh,pbauman/libmesh,90jrong/libmesh,libMesh/libmesh