KEYCLOAK-2759 Fix error message when renaming realm to name that exists

services/src/main/java/org/keycloak/services/resources/admin/RealmAdminResource.java

@@ -266,7 +266,7 @@ public class RealmAdminResource {
         } catch (PatternSyntaxException e) {
             return ErrorResponse.error("Specified regex pattern(s) is invalid.", Response.Status.BAD_REQUEST);
         } catch (ModelDuplicateException e) {
-            throw e;
+            return ErrorResponse.exists("Realm with same name exists");
         } catch (Exception e) {
             logger.error(e.getMessage(), e);
             return ErrorResponse.error("Failed to update realm", Response.Status.INTERNAL_SERVER_ERROR);

services/src/main/java/org/keycloak/services/resources/admin/RealmsAdminResource.java

@@ -151,7 +151,7 @@ public class RealmsAdminResource {
 
             return Response.created(location).build();
         } catch (ModelDuplicateException e) {
-            return ErrorResponse.exists("Realm " + rep.getRealm() + " already exists");
+            return ErrorResponse.exists("Realm with same name exists");
         }
     }