digest jar file instead jar path

In the original source, files extracted from the old jar are cached, preventing you the new jar file contents from adding to fileset, Even if the artifact is changed.

boot/core/src/boot/task_helpers.clj

@@ -132,7 +132,7 @@
                 excl (when v? [regex])
                 jar  (jar-path sym)]
             (core/add-cached-resource
-              fs (digest/md5 jar) (partial pod/unpack-jar jar)
+              fs (digest/md5 (io/file jar)) (partial pod/unpack-jar jar)
               :include incl :exclude excl :mergers pod/standard-jar-mergers)))
         (reduce fileset args))))