Revert "Fixing warning caused by default statement in switch statement that covered all enumeration values"

This reverts commit b5c48f13a1.

AFNetworking/AFHTTPClient.m

@@ -1241,6 +1241,7 @@ typedef enum {
             _phase = AFFinalBoundaryPhase;
             break;
         case AFFinalBoundaryPhase:
+        default:
             _phase = AFEncapsulationBoundaryPhase;
             break;
     }