Fix felling mortality in land use initialisation

[mpaiao]

Description

Minor bug fix in reading in the felling survivorship for large trees. This is currently a deprecated option, but it should be consistent in case users set this variable. This was found when looking at issue #416

Collaborators

@sdeherto

Motivation and Context

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

Testing :

• All new and existing tests passed.