[buildbot] Bump to latest Buildbot release 3.0.2

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/2584d26d71d54eae5c33d16e3fbc84e9c7521670

commit 2584d26d71d54eae5c33d16e3fbc84e9c7521670
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Wed Mar 17 09:36:10 2021 +0100

    Bump to latest Buildbot release 3.0.2
    
    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 a964cce..0b7214c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,5 @@
 variables:
-  BUILDBOT_VERSION: 3.0.1
+  BUILDBOT_VERSION: 3.0.2
 
 include:
   - local: .gitlab/docker.yml