fix ExceptionInInitializerError

HMCLCore/src/main/java/org/jackhuang/hmcl/game/Library.java

@@ -94,7 +94,7 @@ public class Library implements Comparable<Library>, Validation {
     public String getClassifier() {
         if (artifact.getClassifier() == null)
             if (natives != null && natives.containsKey(OperatingSystem.CURRENT_OS))
-                return natives.get(OperatingSystem.CURRENT_OS).replace("${arch}", Platform.PLATFORM.getBit());
+                return natives.get(OperatingSystem.CURRENT_OS).replace("${arch}", Platform.getPlatform().getBit());
             else
                 return null;
         else

HMCLCore/src/main/java/org/jackhuang/hmcl/util/platform/JavaVersion.java

@@ -165,7 +165,7 @@ public final class JavaVersion {
         CURRENT_JAVA = new JavaVersion(
                 currentExecutable,
                 System.getProperty("java.version"),
-                Platform.PLATFORM);
+                Platform.getPlatform());
     }
 
     private static Collection<JavaVersion> JAVAS;

HMCLCore/src/main/java/org/jackhuang/hmcl/util/platform/Platform.java

@@ -47,7 +47,9 @@ public enum Platform {
     /**
      * The platform of current Java Environment.
      */
-    public static final Platform PLATFORM = Architecture.CURRENT.getPlatform();
+    public static Platform getPlatform() {
+        return Architecture.CURRENT.getPlatform();
+    }
 
     /**
      * The json serializer to {@link Platform}.