releng: fix tracecompass-e420.target definition

Commit dbc5d74 added org.eclipse.e4.ui.progress under the orbit
location instead of the Eclipse platform.

To test (use Java 11 JDK):
$ cp rcp/org.eclipse.tracecompass.rcp.product/legacy/tracing.product
rcp/org.eclipse.tracecompass.rcp.product/
$ mvn clean install -DskipTests=true

Signed-off-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Change-Id: I5b63f1eab673f0c6df83ab2a31c135d2a2254de9
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/196864
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>

releng/org.eclipse.tracecompass.target/tracecompass-e4.20.target

@@ -35,7 +35,6 @@
 <unit id="javax.xml.bind" version="0.0.0"/>
 <unit id="javax.activation" version="1.1.0.v201211130549"/>
 <unit id="javax.xml.stream" version="0.0.0"/>
-<unit id="org.eclipse.e4.ui.progress" version="0.0.0"/>
 <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20210602031627/repository/"/>
 </location>
 <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
@@ -56,6 +55,7 @@
 <unit id="org.eclipse.ui.trace" version="0.0.0"/>
 <unit id="org.eclipse.ui.views.log" version="0.0.0"/>
 <unit id="org.eclipse.jdt.junit4.runtime" version="0.0.0"/>
+<unit id="org.eclipse.e4.ui.progress" version="0.0.0"/>
 <repository location="https://download.eclipse.org/eclipse/updates/4.20/R-4.20-202106111600/"/>
 </location>
 <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">