BUG: snappyHexMesh: tutorial failures due to the minEdgeLength changes

f276366a leads to failures in the following tutorials in the Alltest mode:

Application porousSimpleFoam - case incompressible/porousSimpleFoam/straightDuctImplicit: unconfirmed completion
Application snappyHexMesh - case mesh/snappyHexMesh/addLayersToFaceZone: unconfirmed completion

Confirmed that removing f276366a fixes the issues.