Azure / GitLab: Update Docker image

Bring in a newer Docker image to build on that has everything required
for running 'make htmldocs'.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/.azure-pipelines.yml b/.azure-pipelines.yml
index c220958..c2f7f0f 100644
--- a/.azure-pipelines.yml
+++ b/.azure-pipelines.yml
@@ -1,7 +1,7 @@
 variables:
   windows_vm: vs2017-win2016
   ubuntu_vm: ubuntu-18.04
-  ci_runner_image: trini/u-boot-gitlab-ci-runner:bionic-20200112-07Feb2020
+  ci_runner_image: trini/u-boot-gitlab-ci-runner:bionic-20200112-21Feb2020
   # Add '-u 0' options for Azure pipelines, otherwise we get "permission
   # denied" error when it tries to "useradd -m -u 1001 vsts_azpcontainer",
   # since our $(ci_runner_image) user is not root.