[docker-build] replaced main by master in .gitlab-ci.yml

.gitlab-ci.yml

@@ -44,7 +44,7 @@ test_with_coverage:
       - htmlcov
   coverage: "/TOTAL.+ ([0-9]{1,3}%)/"
   rules:
-    - if: $CI_COMMIT_REF_NAME == "main"
+    - if: $CI_COMMIT_REF_NAME == "master"
       when: always
 
 generate_rst:
@@ -58,7 +58,7 @@ generate_rst:
     paths:
       - doc/html
   rules:
-    - if: $CI_COMMIT_REF_NAME == "main"
+    - if: $CI_COMMIT_REF_NAME == "master"
       when: always
 
 pages:
@@ -80,7 +80,7 @@ pages:
     - test_with_coverage
     - generate_rst
   rules:
-    - if: $CI_COMMIT_REF_NAME == "main"
+    - if: $CI_COMMIT_REF_NAME == "master"
       when: always
 
 pypi_upload: