BackupRef: Adapt to PermissionBackend

Change-Id: Ia5ec8a938fb794abc303000dd844125b4366ac19

src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java b/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
index f3777f3..8119b16 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
@@ -37,7 +37,9 @@
 import com.google.gerrit.server.data.RefUpdateAttribute;
 import com.google.gerrit.server.events.RefUpdatedEvent;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.gerrit.server.project.CreateBranch;
+import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.gerrit.server.project.ProjectResource;
 import com.google.inject.Inject;
 import java.io.IOException;
@@ -163,7 +165,9 @@
           } catch (BadRequestException
               | AuthException
               | ResourceConflictException
-              | IOException e) {
+              | IOException
+              | PermissionBackendException
+              | NoSuchProjectException e) {
             log.error(e.getMessage(), e);
           }
         }