pgm/BUILD: Add dependencty to java EWAH

pgm/BUILD: Add dependencty to java EWAH

A fetch to a locally run daemon triggers a runtime exception:

Listening on localhost/127.0.0.1:9418
java.lang.NoClassDefFoundError:
com/googlecode/javaewah/EWAHCompressedBitmap

Add javaEWAH in the deps of the PGM library.

To reproduce:

0. Assume a git repo in <dir-with-repos>/a-repo
1. Run daemon e.g.:
  $ bazel run //org.eclipse.jgit.pgm:jgit -- daemon --export-all=true
  --listen localhost --enable upload-pack <dir-with-repos>

2. Fetch:
  $ git clone git://0.0.0.0:9418/a-repo

Change-Id: I503f9fe45347a5891c3f3de0452b7f300b1e8206