I'm afraid I'm not sure of how the exact law is worded on that one...but, I think that would fall under more of a "between you and your landlord" kind of thing..
Based on my understanding, you are allowed to carry a weapon at your place of business for the most part. As the landlord is the actual property owner, I suppose they do have the right to tell you no guns allowed on what amounts to their personal property, but, I don't believe there's any specific requirement for you to get the property owner's permission within the law. More of a civil thing if you ask me.
Honestly, this is one of those things where I'd say if it's not specifically addressed within your lease or the guidelines/rules/bylaws governing the property...I wouldn't worry about it. And I certainly wouldn't bring it up. :thumsup