Adapt to changes in Gerrit core

AccountCache#maybeGet has been renamed to AccountCache#get.

Change-Id: Ibf207a862b598715213d37796430565e2ae79290
Signed-off-by: Edwin Kempin <ekempin@google.com>
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 be2c749..23e0242 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/singleusergroup/SingleUserGroup.java
@@ -106,7 +106,7 @@
     String ident = username(uuid);
     Optional<AccountState> state;
     if (ident.matches(ACCOUNT_ID_PATTERN)) {
-      state = accountCache.maybeGet(new Account.Id(Integer.parseInt(ident)));
+      state = accountCache.get(new Account.Id(Integer.parseInt(ident)));
     } else if (ident.matches(Account.USER_NAME_PATTERN)) {
       state = accountCache.getByUsername(ident);
     } else {