[releng] Use platform I-builds again

org.eclipse.modisco.releng.tycho/targetPlatforms/nightly.target

diff --git a/org.eclipse.modisco.releng.tycho/targetPlatforms/nightly.target b/org.eclipse.modisco.releng.tycho/targetPlatforms/nightly.target
index 53eb310..0c0c184 100644
--- a/org.eclipse.modisco.releng.tycho/targetPlatforms/nightly.target
+++ b/org.eclipse.modisco.releng.tycho/targetPlatforms/nightly.target
@@ -3,8 +3,8 @@
 <locations>
   <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
     <unit id="org.eclipse.sdk.feature.group" version="0.0.0"/>
-    <repository location="https://download.eclipse.org/releases/latest"/>
-    <!--repository location="https://download.eclipse.org/eclipse/updates/I-builds"/-->
+    <!--repository location="https://download.eclipse.org/releases/latest"/-->
+    <repository location="https://download.eclipse.org/eclipse/updates/I-builds"/>
     <!--repository location="https://download.eclipse.org/releases/2020-12/202011061000"/-->
   </location>
   <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">