allow users without mail address

scm-core/src/main/java/sonia/scm/user/User.java

@@ -73,6 +73,18 @@ public class User
    */
   public User() {}
 
+  /**
+   * Constructs ...
+   *
+   *
+   * @param name
+   */
+  public User(String name)
+  {
+    this.name = name;
+    this.displayName = name;
+  }
+
   /**
    * Constructs ...
    *