Fixed compile warnings

Author: jkasten2

iOS_SDK/OneSignalSDK/Source/OneSignalHelper.h

@@ -60,7 +60,6 @@
 + (UILocalNotification*)prepareUILocalNotification:(NSDictionary*)data :(NSDictionary*)userInfo;
 + (BOOL)verifyURL:(NSString *)urlString;
 + (BOOL)isRemoteSilentNotification:(NSDictionary*)msg;
-@property (class) NSString *lastMessageIdFromAction;
 
 // - Networking
 + (NSNumber*)getNetType;

iOS_SDK/OneSignalSDK/Source/OneSignalHelper.m

@@ -293,6 +293,11 @@ - (NSString*)stringify {
 
 @implementation OneSignalHelper
 
++ (void) resetLocals {
+    [OneSignalHelper lastMessageReceived:nil];
+    _lastMessageIdFromAction = nil;
+}
+
 UIBackgroundTaskIdentifier mediaBackgroundTask;
 
 + (void) beginBackgroundMediaTask {
@@ -505,7 +510,6 @@ + (void)handleNotificationReceived:(OSNotificationDisplayType)displayType {
 }
 
 static NSString *_lastMessageIdFromAction;
-+ (void)setLastMessageIdFromAction:(NSString*)value { _lastMessageIdFromAction = value; }
 
 + (void)handleNotificationAction:(OSNotificationActionType)actionType actionID:(NSString*)actionID displayType:(OSNotificationDisplayType)displayType {
     if (!handleNotificationAction || ![self isOneSignalPayload])

iOS_SDK/OneSignalSDK/Source/OneSignalTracker.m

@@ -51,7 +51,7 @@ @implementation OneSignalTracker
 
 + (void)resetLocals {
     unSentActiveTime = nil;
-    focusBackgroundTask = nil;
+    focusBackgroundTask = 0;
     lastOpenedTime = 0;
     lastOnFocusWasToBackground = YES;
 }

iOS_SDK/OneSignalSDK/UnitTests/UnitTests.m

@@ -437,8 +437,9 @@ - (void)setUp {
 
     preferredLanguagesArray = @[@"en-US"];
 
-    [OneSignalHelper lastMessageReceived:nil];
-    OneSignalHelper.lastMessageIdFromAction = nil;
+    [OneSignalHelper performSelector:NSSelectorFromString(@"resetLocals")];
+    
+    
     [OneSignal setValue:nil forKeyPath:@"lastAppActiveMessageId"];
     [OneSignal setValue:nil forKeyPath:@"lastnonActiveMessageId"];
     [OneSignal setValue:@0 forKeyPath:@"mSubscriptionStatus"];