Fix missing app icon in Showcase page

docs/showcase.md

@@ -279,7 +279,7 @@ permalink: /showcase.html
 		</td>
 		
 		<td align="center" valign="top">
-		<a href="https://apps.apple.com/us/app/longwalks-a-conversation-app/id1412531085"><img class="roundrect" src="https://media.licdn.com/dms/image/C560BAQEEl1y2TT6fxg/company-logo_200_200/0?e=2159024400&v=beta&t=ZdIFP0AXZiAHgw2_0sJHvCv9z6dO7JF8O-fnCqc2530" style="width:100px;height:100px;"></a>
+		<a href="https://apps.apple.com/us/app/longwalks-a-conversation-app/id1412531085"><img class="roundrect" src="https://is3-ssl.mzstatic.com/image/thumb/Purple123/v4/10/fb/7c/10fb7c7d-4d1b-6058-56c7-baf81d9c856e/AppIcon-0-1x_U007emarketing-0-0-GLES2_U002c0-512MB-sRGB-0-0-0-85-220-0-0-0-10.png/230x0w.jpg" style="width:100px;height:100px;"></a>
 		<br /> 
 		<b>Longwalks</b>
 		</td>