fix nullpointerexcpetion on first login

scm-webapp/src/main/java/sonia/scm/group/xml/XmlGroupDatabase.java

@@ -59,6 +59,20 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 public class XmlGroupDatabase
 {
 
+  /**
+   * Constructs ...
+   *
+   */
+  public XmlGroupDatabase()
+  {
+    long c = System.currentTimeMillis();
+
+    creationTime = c;
+    lastModified = c;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
   /**
    * Method description
    *

scm-webapp/src/main/java/sonia/scm/group/xml/XmlGroupManager.java

@@ -209,7 +209,6 @@ public class XmlGroupManager extends AbstractGroupManager
     if (groupDB == null)
     {
       groupDB = new XmlGroupDatabase();
-      groupDB.setCreationTime(System.currentTimeMillis());
     }
   }