fix: crash with md4 hash (#198)

Author: alexander-akait

lib/getHashDigest.js

@@ -67,6 +67,10 @@ function getHashDigest(buffer, algorithm, digestType, maxLength) {
   } else if (algorithm === "md4") {
     if (createMd4 === undefined) {
       createMd4 = require("./hash/md4");
+
+      if (BatchedHash === undefined) {
+        BatchedHash = require("./hash/BatchedHash");
+      }
     }
 
     hash = new BatchedHash(createMd4());