Merge pull request #4 from larsw/fix-central-does-not-exist

Fix warning about central not existing

sync/settings.xml

@@ -1,4 +1,9 @@
 <settings>
+  <profiles>
+    <profile>
+      <id>central</id>
+    </profile>
+  </profiles>
   <mirrors>
     <mirror>
       <id>central</id>