[nit] OneSignalLog remove extraneous interface methods

* These are already part of the OSDebug protocol so no need to state them again

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OneSignalLog.h

@@ -43,7 +43,5 @@ typedef NS_ENUM(NSUInteger, ONE_S_LOG_LEVEL) {
 
 @interface OneSignalLog : NSObject<OSDebug>
 + (Class<OSDebug>)Debug;
-+ (void)setLogLevel:(ONE_S_LOG_LEVEL)logLevel;
-+ (void)setAlertLevel:(ONE_S_LOG_LEVEL)logLevel;
 + (void)onesignalLog:(ONE_S_LOG_LEVEL)logLevel message:(NSString* _Nonnull)message;
 @end