Change deprecated iconUrl icon to icon tag in nuspec files

DEVSIX-3527

Author: EvgenyB1001

ITSC-avatar.png

@@ -8,7 +8,7 @@
     <owners>iText Software</owners>
     <licenseUrl>https://www.gnu.org/licenses/agpl.html</licenseUrl>
     <projectUrl>https://itextpdf.com/en/products/itext-7/pdfhtml</projectUrl>
-    <iconUrl>https://itextpdf.com/sites/default/files/ITSC-avatar.png</iconUrl>
+    <icon>ITSC-avatar.png</icon>
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <description>pdfHTML is an iText 7 add-on for C# (.NET) that allows you to easily convert HTML and CSS into standards compliant PDFs that are accessible, searchable and usable for indexing.</description>
     <summary>pdfHTML is an iText 7 add-on that lets you to parse (X)HTML snippets and the associated CSS and converts them to PDF.</summary>
@@ -35,5 +35,6 @@
     <file src="itext\itext.html2pdf\bin\Release\netstandard1.6\itext.html2pdf.xml" target="lib\netstandard1.6" />
     <file src="gnu-agpl-v3.0.md" target="" />
     <file src="LICENSE.md" target="" />
+	<file src="ITSC-avatar.png" target="" />
   </files>
 </package>