[releng] Switch to Oxygen.1a of Eclipse Platform

Change-Id: Iabe4995a53a87076c24d1accbc7eb613e284f1bb
Signed-off-by: Andreas Sewe <andreas.sewe@codetrails.com>
diff --git a/releng/targets/oxygen/oxygen.target b/releng/targets/oxygen/oxygen.target
index 9c2dd8f..b79ef27 100644
--- a/releng/targets/oxygen/oxygen.target
+++ b/releng/targets/oxygen/oxygen.target
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<?pde version="3.8"?><target name="Target Definition for Eclipse Oxygen (4.7)" sequenceNumber="4">
+<?pde version="3.8"?><target name="Target Definition for Eclipse Oxygen (4.7)" sequenceNumber="5">
 <locations>
 <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="slicer" includeSource="true" type="InstallableUnit">
 <unit id="org.eclipse.ecf.core.feature.feature.group" version="0.0.0"/>
 <unit id="org.eclipse.ecf.filetransfer.feature.feature.group" version="0.0.0"/>
 <unit id="org.eclipse.equinox.p2.sdk.feature.group" version="0.0.0"/>
 <unit id="org.eclipse.sdk.ide" version="0.0.0"/>
-<repository location="http://download.eclipse.org/eclipse/updates/4.7-M-builds/M-4.7.1RC1-201708170500/"/>
+<repository location="http://download.eclipse.org/eclipse/updates/4.7/R-4.7.1a-201710090410/"/>
 </location>
 <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="slicer" includeSource="true" type="InstallableUnit">
 <unit id="org.eclipse.emf.sdk.feature.group" version="0.0.0"/>