Use last released LinuxTools docker

At the moment there are some resolution issues on the nightly
versions of LinuxTools docker components, so for now use the
latest release rather than nightly.

See eclipse-linuxtools/org.eclipse.linuxtools#232

releng/org.eclipse.cdt.target/cdt.target

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde version="3.8"?>
-<target name="cdt" sequenceNumber="140">
+<target name="cdt" sequenceNumber="141">
 	<locations>
 		<location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
 			<repository location="https://download.eclipse.org/cbi/updates/license/" />
@@ -19,7 +19,7 @@
 			<unit id="org.eclipse.egit.feature.group" version="0.0.0" />
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/linuxtools/updates-docker-nightly/" />
+			<repository location="https://download.eclipse.org/linuxtools/update-docker" />
 			<unit id="org.eclipse.linuxtools.docker.feature.feature.group" version="0.0.0" />
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">