BUCK: fix Implementation-Version in replication plugin

 buck build plugins/replication

produces broken META-INF/MANIFEST.MF in replication.jar file.

What Buck is doing is to issue that command (shorten):

  jar cfm replication.jar buck-out/gen/plugins/replication/MANIFEST.MF \
          buck-out/gen/.../replication__plugin.jar \
          buck-out/gen/lib/commons/io/commons-io-1.4.jar

and the content of correct input MANIFEST.MF file get overriden with the
content of MANIFEST.MF from commons-io-1.4.jar.

So instead of expected Gerrit version:
Implementation-Version: v2.7-rc4-1348-g36c61aa

we get:
Implementation-Version: 1.4

Change-Id: If93b1c64e8199c858aa55505352f631790a029ff
diff --git a/lib/commons/BUCK b/lib/commons/BUCK
index 6f412e4..fd066ef 100644
--- a/lib/commons/BUCK
+++ b/lib/commons/BUCK
@@ -73,6 +73,7 @@
   id = 'commons-io:commons-io:1.4',
   sha1 = 'a8762d07e76cfde2395257a5da47ba7c1dbd3dce',
   license = 'Apache2.0',
+  exclude = ['META-INF/MANIFEST.MF'],
 )
 
 maven_jar(