Use final release URL of Eclipse Platform

Change-Id: I375057d8615e5f069a8d744e63bdbc5a94b69819
Signed-off-by: Markus Knauer <mknauer@eclipsesource.com>
diff --git a/releng/org.eclipse.rap.build/pom.xml b/releng/org.eclipse.rap.build/pom.xml
index 0e87f4f..3a14fe6 100644
--- a/releng/org.eclipse.rap.build/pom.xml
+++ b/releng/org.eclipse.rap.build/pom.xml
@@ -31,7 +31,7 @@
     <cbi-plugins.version>1.1.2</cbi-plugins.version>
     <jetty-repo.url>https://download.eclipse.org/jetty/updates/jetty-bundles-9.x/9.4.26.v20200117/</jetty-repo.url>
     <orbit-repo.url>https://download.eclipse.org/tools/orbit/downloads/2020-03/</orbit-repo.url>
-    <platform-repo.url>https://download.eclipse.org/eclipse/updates/4.15milestones/S-4.15RC2-202003050155/</platform-repo.url>
+    <platform-repo.url>https://download.eclipse.org/eclipse/updates/4.15/R-4.15-202003050155/</platform-repo.url>
     <rap-extra-repo.url>https://build.eclipse.org/rt/rap/base-platforms/3.12/extra-dependencies/</rap-extra-repo.url>
     <license-repo.url>https://download.eclipse.org/cbi/updates/license/</license-repo.url>
     <!-- The build type, N for nighty builds, S for stable builds. S-builds will be signed. -->