fix: inverted isEmpty method on ComponentStyle

Fixes SpigotMC#3610
Relates to SpigotMC#3569 and 737d545

chat/src/main/java/net/md_5/bungee/api/chat/ComponentStyle.java

@@ -186,15 +186,15 @@ public Boolean isObfuscatedRaw()
     }
 
     /**
-     * Returns whether this style has any formatting explicitly set.
+     * Returns whether this style has no formatting explicitly set.
      *
-     * @return true if at least one value is set, false if none are set
+     * @return true if no value is set, false if at least one is set
      */
     public boolean isEmpty()
     {
-        return color != null || font != null || bold != null
-                || italic != null || underlined != null
-                || strikethrough != null || obfuscated != null;
+        return color == null && font == null && bold == null
+                && italic == null && underlined == null
+                && strikethrough == null && obfuscated == null;
     }
 
     @Override