Use first non-zero length Elem to determine h_min.
Use first non-zero length Elem to determine h_min.

We only set h_min in this way if it has not been previously
updated. This ensures that h_min is the min over both meshes being
stitched.

Co-authored-by: John W. Peterson <01ed71589468ceccd639d7d4357a488f616de824@gmail.com>

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