remove ${promote.prefix} from incubator pom

Change-Id: I3732fd0d26870cb8820f28ce14a2350ac45be9b5
diff --git a/org.eclipse.mylyn.incubator-site/pom.xml b/org.eclipse.mylyn.incubator-site/pom.xml
index d4cb269..d685d65 100644
--- a/org.eclipse.mylyn.incubator-site/pom.xml
+++ b/org.eclipse.mylyn.incubator-site/pom.xml
@@ -119,7 +119,7 @@
                   <property name="skipPromote" value="${promote.skip}"/>
                   
                   <property name="version" value="${unqualifiedVersion}"/>
-                  <property name="qualifier" value="${promote.prefix}${buildQualifier}"/>
+                  <property name="qualifier" value="${buildQualifier}"/>
                 </ant>
                 <echo file="${project.build.directory}/version.properties">
                   <![CDATA[