remove unused _maven_jar

Change-Id: I1578116c2787aa7c201a8ab8091bccb457995c0f

tools/bzl/maven_jar.bzl

diff --git a/tools/bzl/maven_jar.bzl b/tools/bzl/maven_jar.bzl
deleted file mode 100644
index 35ea8ce..0000000
--- a/tools/bzl/maven_jar.bzl
+++ /dev/null
@@ -1,3 +0,0 @@
-load("@com_googlesource_gerrit_bazlets//tools:maven_jar.bzl", _maven_jar = "maven_jar")
-
-maven_jar = _maven_jar