[buildbot] Bump to latest Buildbot release 3.2.0

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/ffa094e833733c96f14420c26605f02be7f0fc36

commit ffa094e833733c96f14420c26605f02be7f0fc36
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Mon Jun 28 08:39:14 2021 +0200

    Bump to latest Buildbot release 3.2.0
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b8d1974..07a0407 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,5 @@
 variables:
-  BUILDBOT_VERSION: 3.0.2
+  BUILDBOT_VERSION: 3.2.0
   OPENWRT_VERSION: $CI_COMMIT_SHORT_SHA
 
 include: