Make user.ownedRole relationship @OneToOne.

Change-Id: I8c0194960e15192ba36834fa666c3f9fb2826df8
diff --git a/src/main/java/eu/mulk/mulkcms2/benki/accesscontrol/Role.java b/src/main/java/eu/mulk/mulkcms2/benki/accesscontrol/Role.java
index 131fb69..b7dd6fc 100644
--- a/src/main/java/eu/mulk/mulkcms2/benki/accesscontrol/Role.java
+++ b/src/main/java/eu/mulk/mulkcms2/benki/accesscontrol/Role.java
@@ -17,6 +17,7 @@
 import javax.persistence.JoinTable;
 import javax.persistence.ManyToMany;
 import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
 import javax.persistence.Table;
 
 @Entity
@@ -59,8 +60,8 @@
   @OneToMany(mappedBy = "role", fetch = FetchType.LAZY)
   public Collection<UserRole> directUsers;
 
-  @OneToMany(mappedBy = "ownedRole", fetch = FetchType.LAZY)
-  public Collection<User> owningUsers;
+  @OneToOne(mappedBy = "ownedRole", fetch = FetchType.LAZY)
+  public User owningUsers;
 
   @ManyToMany(mappedBy = "effectiveRoles", fetch = FetchType.LAZY)
   public Collection<User> effectiveUsers;
diff --git a/src/main/java/eu/mulk/mulkcms2/benki/users/User.java b/src/main/java/eu/mulk/mulkcms2/benki/users/User.java
index 90b3318..6e16903 100644
--- a/src/main/java/eu/mulk/mulkcms2/benki/users/User.java
+++ b/src/main/java/eu/mulk/mulkcms2/benki/users/User.java
@@ -16,8 +16,8 @@
 import javax.persistence.JoinColumn;
 import javax.persistence.JoinTable;
 import javax.persistence.ManyToMany;
-import javax.persistence.ManyToOne;
 import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
 import javax.persistence.Table;
 
 @Entity(name = "BenkiUser")
@@ -79,7 +79,7 @@
   @OneToMany(mappedBy = "user", fetch = FetchType.LAZY)
   public Collection<UserRsaKey> rsaKeys;
 
-  @ManyToOne(fetch = FetchType.LAZY)
+  @OneToOne(fetch = FetchType.LAZY)
   @JoinColumn(name = "role", referencedColumnName = "id", nullable = false)
   public Role ownedRole;