Remove unused maven_jar.bzl

Change-Id: If345372a5b8fc77f37bb9466f440850e2501f292
diff --git a/tools/bzl/maven_jar.bzl b/tools/bzl/maven_jar.bzl
deleted file mode 100644
index 2eabedb..0000000
--- a/tools/bzl/maven_jar.bzl
+++ /dev/null
@@ -1 +0,0 @@
-load("@com_googlesource_gerrit_bazlets//tools:maven_jar.bzl", "maven_jar")