Bump buildifier version to 0.26.0

Workspace status command was re-written in Python in: [1].

[1] https://github.com/bazelbuild/buildtools/pull/631

Change-Id: I891f1a0c51a9f76ecd4a045debdbce92a0c02877
diff --git a/jenkins-docker/slave-bazel-nocache/Dockerfile b/jenkins-docker/slave-bazel-nocache/Dockerfile
index 522ee5e..0222661 100644
--- a/jenkins-docker/slave-bazel-nocache/Dockerfile
+++ b/jenkins-docker/slave-bazel-nocache/Dockerfile
@@ -17,7 +17,7 @@
     git clone https://github.com/bazelbuild/buildtools.git && \
     cd buildtools && \
     git checkout ${BUILDIFIER_VER} && \
-    bazel build --workspace_status_command=`pwd`/status.sh //buildifier && \
+    bazel build --workspace_status_command=`pwd`/status.py //buildifier && \
     cp bazel-bin/buildifier/linux_amd64_stripped/buildifier /usr/bin && \
     rm -rf /tmp/buildtools && \
     buildifier --version'
diff --git a/jenkins-docker/slave-bazel-nocache/Makefile b/jenkins-docker/slave-bazel-nocache/Makefile
index a5682d6..b522ffe 100644
--- a/jenkins-docker/slave-bazel-nocache/Makefile
+++ b/jenkins-docker/slave-bazel-nocache/Makefile
@@ -1,7 +1,7 @@
 NO_CACHE=false
 IMAGE=gerritforge/gerrit-ci-slave-bazel:debian-stretch-nocache
 BAZEL_VER=0.26.1
-BUILDIFIER_VER=0.22.0
+BUILDIFIER_VER=0.26.0
 BAZELISK_VER=0.0.7
 
 # Targets