[CognitoAuth] Fix duplicate client creation

Lead to double binding to service

Author: rlatapy-luna

aws-android-sdk-cognitoauth/src/main/java/com/amazonaws/mobileconnectors/cognitoauth/Auth.java

@@ -159,7 +159,6 @@ private Auth(final Context context,
         this.signOutRedirectUri = signOutRedirectUri;
         this.scopes = scopes;
         this.user = new AuthClient(context, this);
-        this.user = new AuthClient(context, this);
         this.user.setUserHandler(userHandler);
         this.userPoolId = userPoolId;
         this.advancedSecurityDataCollectionFlag = advancedSecurityDataCollectionFlag;