Insurance — Wind and hail — Where policy issued to condominium complex was for named perils of wind and hail, insured had burden of showing that damage to roofs of condominium buildings was caused by the named peril of wind — Trial court erred by granting directed verdict for insured without allowing insurer to present evidence of non-wind related causes of damage — Insurer was not required to plead the existing damage exclusion as an affirmative defense