#792 Include registration date into purging logic

- Take MAX(reg_date, login_date) as timestamp to compare against
- Remove the second "all" parameter to include entries with 0 registration date -> we expect registration date to always be set to the current date, so the parameter becomes obsolete

src/main/java/fr/xephi/authme/datasource/CacheDataSource.java

@@ -137,8 +137,8 @@ public class CacheDataSource implements DataSource {
     }
 
     @Override
-    public Set<String> getRecordsToPurge(long until, boolean includeEntriesWithLastLoginZero) {
-        return source.getRecordsToPurge(until, includeEntriesWithLastLoginZero);
+    public Set<String> getRecordsToPurge(long until) {
+        return source.getRecordsToPurge(until);
     }
 
     @Override