Remove unused ReviewDb

Change-Id: I722d9ee1761f15b49da2c6a12e2638ead6390d77
diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewers/AddReviewers.java b/src/main/java/com/googlesource/gerrit/plugins/reviewers/AddReviewers.java
index db676e0..34a5cc2 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewers/AddReviewers.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewers/AddReviewers.java
@@ -21,7 +21,6 @@
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.reviewdb.client.Account;
-import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.util.RequestContext;
@@ -37,8 +36,6 @@
   protected final IdentifiedUser.GenericFactory identifiedUserFactory;
   protected final ChangeInfo changeInfo;
 
-  private ReviewDb db = null;
-
   AddReviewers(
       ThreadLocalRequestContext tl,
       GerritApi gApi,
@@ -67,10 +64,6 @@
       addReviewers(getReviewers(), changeInfo);
     } finally {
       tl.setContext(old);
-      if (db != null) {
-        db.close();
-        db = null;
-      }
     }
   }
 
diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewers/SuggestProjectReviewers.java b/src/main/java/com/googlesource/gerrit/plugins/reviewers/SuggestProjectReviewers.java
index 806b4b4..cef7e4f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewers/SuggestProjectReviewers.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewers/SuggestProjectReviewers.java
@@ -19,7 +19,6 @@
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.Account;
-import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.permissions.PermissionBackend;
 import com.google.gerrit.server.permissions.PermissionBackendException;
@@ -30,7 +29,6 @@
 import com.google.gerrit.server.restapi.change.SuggestReviewers;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
-import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.List;
 import org.eclipse.jgit.errors.ConfigInvalidException;