Bug 573962 - Update product version number to 4.21 across build script

Change-Id: Ia60c93f54b17842ab1f37039b67e2c9102a11e62
Signed-off-by: Sravan Kumar Lakkimsetti <sravankumarl@in.ibm.com>
Reviewed-on: https://git.eclipse.org/r/c/equinox/rt.equinox.p2/+/181362
diff --git a/org.eclipse.equinox.p2.releng/default.target b/org.eclipse.equinox.p2.releng/default.target
index a02fdc0..12933d3 100644
--- a/org.eclipse.equinox.p2.releng/default.target
+++ b/org.eclipse.equinox.p2.releng/default.target
@@ -6,7 +6,7 @@
 <unit id="org.eclipse.platform.sdk" version="0.0.0"/>
 <unit id="org.eclipse.core.tests.harness" version="0.0.0"/>
 <unit id="org.eclipse.test.feature.group" version="0.0.0"/>
-<repository location="https://download.eclipse.org/eclipse/updates/4.19-I-builds"/>
+<repository location="https://download.eclipse.org/eclipse/updates/4.21-I-builds"/>
 </location>
 <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
 <unit id="org.bouncycastle.bcprov" version="0.0.0"/>