Share Extension: Fix crash on a weak self
Share Extension: Fix crash on a weak self

Reported only by app store because we do not catch crashes from the share extension nor siri extension.

vector-im/riot-ios,vector-im/vector-ios,vector-im/riot-ios,vector-im/vector-ios,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios,vector-im/riot-ios,vector-im/riot-ios