finally fix default config issue (mabe)

i didn't test it but
blackilykat found the fix ig

src/main/java/land/chipmunk/chipmunkmod/ChipmunkMod.java

@@ -50,7 +50,7 @@ public class ChipmunkMod implements ModInitializer {
     final File file = CONFIG_FILE;
 
     if (!file.exists()) {
-      InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("default_config.json");
+      InputStream is = ChipmunkMod.class.getClassLoader().getResourceAsStream("default_config.json");
       BufferedReader reader = new BufferedReader(new InputStreamReader(is));
 
       final StringBuilder sb = new StringBuilder();