Fix WORKSPACE (#3175)
Fix WORKSPACE (#3175)

* WORKSPACE: actually run icu4j_compile()

Gives the following warning:

An existing maven_jar rule 'com_ibm_icu_icu4j' was already loaded with a sha1 value of 'db9fd4b4c189cf1518db14c67d14a2cfcfbe59f6'.  Overwriting this with the requested value ('385682b7fff53cd5ac2cad0fdb4658a7b97e9475').
You *should* either remove the pre-existing rule from your WORKSPACE or exclude it from loading by rules_maven.

* Remove unused antlr4

We only actually use the runtime library

batfish/batfish,intentionet/batfish,arifogel/batfish,batfish/batfish,batfish/batfish,dhalperi/batfish,arifogel/batfish,intentionet/batfish,dhalperi/batfish,arifogel/batfish,intentionet/batfish,intentionet/batfish,dhalperi/batfish,intentionet/batfish