Calling requestKeyedTokenWithPublicKey when the network connection is disconnected will cause the app to crash.

[Clintzhu1]

Thread 9 Crashed:
0 libobjc.A.dylib 0x1a1253a7c objc_retain + 16
1 MonetaryMobileToken 0x10242ffe4 -[RestUtil sendRequestToURL:forRequestType:withBody:andKey:error:] + 420
2 MonetaryMobileToken 0x10242b3fc +[TokenizationController getTokenForAccount:cvv:andExpiration:withPublicKey:andEncKey:error:] + 840
3 MonetaryMobileToken 0x102430c28 __78-[MonetaryTokenizer tokenizeAccount:cvv:expiration:andPublicKey:withDelegate:]_block_invoke + 156
4 libdispatch.dylib 0x1af612320 _dispatch_call_block_and_release + 32
5 libdispatch.dylib 0x1af613eac _dispatch_client_callout + 20
6 libdispatch.dylib 0x1af616f8c _dispatch_queue_override_invoke + 788
7 libdispatch.dylib 0x1af625944 _dispatch_root_queue_drain + 396
8 libdispatch.dylib 0x1af626158 _dispatch_worker_thread2 + 164
9 libsystem_pthread.dylib 0x207502da0 _pthread_wqthread + 228
10 libsystem_pthread.dylib 0x207502b7c start_wqthread + 8