[releng] Fix p2 repo for ptp remote

The URL we were using was a milestone location - this location is
the release location. The milestone location has since been deleted.

Change-Id: I2e29fbf36d51d17cd53754afc5175275257f0983
diff --git a/releng/CDT.setup b/releng/CDT.setup
index e87c958..1948ff9 100644
--- a/releng/CDT.setup
+++ b/releng/CDT.setup
@@ -196,7 +196,7 @@
         <repository
             url="https://download.eclipse.org/tools/orbit/downloads/drops/R20210223232630/repository"/>
         <repository
-            url="https://download.eclipse.org/tools/ptp/updates/remote/3.0.1/"/>
+            url="https://download.eclipse.org/tools/ptp/remote/releases/3.0/remote-3.0.1/"/>
       </repositoryList>
     </targlet>
   </setupTask>