fixing crash when encoding url in ios 11 [https://trello.com/c/wd5ISvna]
fixing crash when encoding url in ios 11 [https://trello.com/c/wd5ISvna]

qiscus/qiscus-sdk-ios,qiscus/qiscus-sdk-ios,qiscus/qiscus-sdk-ios,qiscus/qiscus-sdk-ios,qiscus/qiscus-sdk-ios