Fixes download button for 'my models'

Author: AurL

UnityGLTF/Assets/UnityGLTF/Scripts/Sketchfab/AssetBrowser/SketchfabBrowserManager.cs

@@ -96,6 +96,14 @@ public void parseModelData(JSONNode node)
 			hasAnimation = node["animationCount"].AsInt > 0 ? "Yes" : "No";
 			licenseJson = node["license"].AsObject;
 
+			// "My models" results don't have any license as they are "private download"
+			// for the author.
+			if(licenseJson.ToString() == "{}")
+			{
+				isModelAvailable = archiveSize > 0;
+				return;
+			}
+
 			formattedLicenseRequirements = licenseJson["requirements"];
 
 			if (formattedLicenseRequirements.Length > 0)