fix typo in tests script

releng.wtpbuilder/distribution/incubator.tests/testScripts/test.xml

@@ -48,7 +48,7 @@
             file="${testRoot}/test2.properties" />
     </target>
     <target
-        name="runtest"
+        name="runtests"
         description="Runs ant on the test.xml for a specified plugin.">
         <available
             file="${eclipse-home}/plugins/${testPlugin}/test.xml"