Added missing file: prefix.

releng/org.yakindu.sct.releng/promote.xml

@@ -14,7 +14,7 @@
 		<p2.mirror>
 			<repository location="file:/${local.update.site}" name="Yakindu SCT 2 upate-site" />
 			<source>
-				<repository location="${env.promotionSource}/artifact/buildDirectory/build_local_repository/" />
+				<repository location="file:/${env.promotionSource}/artifact/buildDirectory/build_local_repository/" />
 			</source>
 		</p2.mirror>
 	</target>