Fix UtilTest tests failing if locale is not English (#6397)

Author: phinner

Essentials/src/test/java/com/earth2me/essentials/UtilTest.java

@@ -11,6 +11,7 @@
 import java.util.Calendar;
 import java.util.GregorianCalendar;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Set;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -25,6 +26,7 @@ public void setUp() {
         MockBukkit.mock();
         Essentials.TESTING = true;
         ess = MockBukkit.load(Essentials.class);
+        ess.getI18n().updateLocale(Locale.ENGLISH.toLanguageTag());
     }
 
     @AfterEach