Fix broken url to "Better Bloom Filter" paper

src/java/org/apache/cassandra/utils/BloomFilter.java

@@ -53,7 +53,7 @@ protected long[] initialValue()
 
     // Murmur is faster than an SHA-based approach and provides as-good collision
     // resistance.  The combinatorial generation approach described in
-    // http://www.eecs.harvard.edu/~kirsch/pubs/bbbf/esa06.pdf
+    // https://www.eecs.harvard.edu/~michaelm/postscripts/tr-02-05.pdf
     // does prove to work in actual tests, and is obviously faster
     // than performing further iterations of murmur.
     protected abstract void hash(ByteBuffer b, int position, int remaining, long seed, long[] result);