[1.7.4] Spellcrusher does not remove Disruption Shield

[Erenion]

The Spellcrusher artefact greatmaus is supposed to remove Disruption Shield.
However, it checks for

target:attr("disruption_shield")

to find out whether the target has said shield active, which is an attribute that never comes up anywhere else in the code.
Therefore, it does not actually remove Disruption Shield.