Remove retain warning from cocoapods spec
Remove retain warning from cocoapods spec

AzureAD/microsoft-authentication-library-for-objc,AzureAD/microsoft-authentication-library-for-objc,AzureAD/microsoft-authentication-library-for-objc,AzureAD/microsoft-authentication-library-for-objc,AzureAD/microsoft-authentication-library-for-objc