gitlab-ci: update the image version

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 7f654438c4bbb8605f0867d17b9e79882de11433)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

.gitlab-ci.yml

@@ -4,7 +4,7 @@
 # It needs to be regenerated every time a defconfig is added, using
 # "make .gitlab-ci.yml".
 
-image: buildroot/base:20191027.2027
+image: buildroot/base:20200814.2228
 
 .check_base:
     rules:

.gitlab-ci.yml.in

@@ -4,7 +4,7 @@
 # It needs to be regenerated every time a defconfig is added, using
 # "make .gitlab-ci.yml".
 
-image: buildroot/base:20191027.2027
+image: buildroot/base:20200814.2228
 
 .check_base:
     rules: