(1) Non-compliance with a warranty is excused when, by reason of a change of circumstances, the warranty ceases to be applicable to the circumstances of the contract, or when compliance with the warranty is rendered unlawful by any subsequent law.
     (2) Where a warranty is broken, the assured cannot avail himself of the defence that the breach has been remedied, and the warranty complied with before loss.
     (3) A breach of warranty may be waived by the insurer.