make the test at least test the library it's calling

Author: celeduc

src/test/java/io/ipfs/multihash/MultihashTest.java

@@ -13,7 +13,7 @@ public void base58Test() {
         for (String example: examples) {
             byte[] output = Base58.decode(example);
             String encoded = Base58.encode(output);
-            if (!encoded.equals(encoded))
+            if (!encoded.equals(example))
                 throw new IllegalStateException("Incorrect base58! " + example + " => " + encoded);
         }
     }