Adapt SingleUserGroup#suggest() to new interface

Change-Id: I59a0c366d0eaa97a9f1954d3b59137a249a6371d

src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java b/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java
index 0cc44ea..21dc1a6 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java
@@ -35,6 +35,7 @@
 import com.google.gerrit.server.account.GroupMembership;
 import com.google.gerrit.server.account.ListGroupMembership;
 import com.google.gerrit.server.project.ProjectControl;
+import com.google.gerrit.server.project.ProjectState;
 import com.google.gerrit.server.query.account.AccountPredicates;
 import com.google.gerrit.server.query.account.AccountQueryBuilder;
 import com.google.gerrit.server.query.account.AccountQueryProcessor;
@@ -142,7 +143,7 @@
   }
 
   @Override
-  public Collection<GroupReference> suggest(String name, @Nullable ProjectControl project) {
+  public Collection<GroupReference> suggest(String name, @Nullable ProjectState project) {
     try {
       return Lists.transform(
           queryProvider