Fix a compilation warning on Iphone 6+
Fix a compilation warning on Iphone 6+

matrix-org/matrix-ios-console,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios,matrix-org/matrix-ios-console,vector-im/riot-ios,vector-im/riot-ios,vector-im/vector-ios,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios