Use locale independent formatting strings

Author: MinnDevelopment

src/main/java/club/minnced/discord/webhook/WebhookClient.java

@@ -39,10 +39,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Objects;
+import java.util.*;
 import java.util.concurrent.*;
 import java.util.regex.Matcher;
 
@@ -82,7 +79,7 @@ protected WebhookClient(
         this.id = id;
         this.threadId = threadId;
         this.parseMessage = parseMessage;
-        this.url = String.format(WEBHOOK_URL, Long.toUnsignedString(id), token);
+        this.url = String.format(Locale.ROOT, WEBHOOK_URL, Long.toUnsignedString(id), token);
         this.pool = pool;
         this.bucket = new Bucket();
         this.queue = new LinkedBlockingQueue<>();

src/main/java/club/minnced/discord/webhook/receive/ReadonlyUser.java

@@ -22,6 +22,8 @@
 import org.json.JSONPropertyName;
 import org.json.JSONString;
 
+import java.util.Locale;
+
 /**
  * Readonly POJO of a discord user
  */
@@ -56,7 +58,7 @@ public long getId() {
      * @return The discriminator
      */
     public String getDiscriminator() {
-        return String.format("%04d", discriminator);
+        return String.format(Locale.ROOT, "%04d", discriminator);
     }
 
     /**