Remove deprecated properties from docs that can switch to old model

Author: nade7o

controls/pdfviewer/getting-started.md

@@ -17,9 +17,7 @@ previous_url: pdfviewer-getting-started
 
 This article will help you quickly get started with __RadPdfViewer__. To start off, drag and drop __RadPdfViewer__ the control from the toolbox to your form. 
 
-> As of R1 2021 __RadPdfViewer__ is optimized to work together with [RadPdfProcessing](https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/overview) library model. The idea is to unify the underlying architecture of __RadPdfViewer__ and __PdfProcessing__ to allow feature parity. __RadPdfViewer__ uses the new model by default. However, the user can easily switch to the old model by using the __UsePdfProcessingModel__ and __UsePdfProcessingModelDefaultValue__  boolean properties. They should be set before loading a PDF document.
-* __UsePdfProcessingModel__ property: Gets or sets a value indicating weather the __RadPdfViewer__ should use the new __RadPdfProcessing__ rendering model on document import. The default value is _true_. If this property is set to _false_ the __RadPdfViewer__ will fall-back internally to use the old model.
-* __UsePdfProcessingModelDefaultValue__ property: Gets or sets a default value for __UsePdfProcessingModel__ property. The default value is _true_. When __RadPdfViewer.UseOldRenderingDefaultValue__ is set all __RadPdfViewer__ instances will use the specified model.
+> As of R1 2021 __RadPdfViewer__ is optimized to utilize the [RadPdfProcessing](https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/overview) library model. The idea is to unify the underlying architecture of __RadPdfViewer__ and __Telerik PdfProcessing Library__ to allow feature parity.
 
 Once you have __RadPdfViewer__, you can set the __ViewerMode__ option to a desired value.