Adapt to changes in Gerrit core

In Ia177bc8cfd6 InternalGroup was moved to the entities package.

Change-Id: I4707ac273f9090096493d50e0ca1427c6494df58
diff --git a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/GetConfig.java b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/GetConfig.java
index 3cca663..16e200a 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/GetConfig.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/GetConfig.java
@@ -16,6 +16,7 @@
 
 import com.google.common.base.Strings;
 import com.google.gerrit.entities.AccountGroup;
+import com.google.gerrit.entities.InternalGroup;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.common.GroupInfo;
 import com.google.gerrit.extensions.restapi.Response;
@@ -24,7 +25,6 @@
 import com.google.gerrit.server.config.ConfigResource;
 import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.config.PluginConfigFactory;
-import com.google.gerrit.server.group.InternalGroup;
 import com.google.gerrit.server.group.InternalGroupDescription;
 import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.gerrit.server.restapi.group.GroupJson;