[mod] add Python 3.9 support

.github/workflows/integration.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     steps:
     - name: Checkout
       uses: actions/checkout@v2

Makefile

@@ -14,7 +14,7 @@ include utils/makefile.include
 PYOBJECTS = searx
 DOC       = docs
 PY_SETUP_EXTRAS ?= \[test\]
-PYLINT_SEARX_DISABLE_OPTION := I,C,R,W0105,W0212,W0511,W0603,W0613,W0621,W0702,W0703,W1401
+PYLINT_SEARX_DISABLE_OPTION := I,C,R,W0105,W0212,W0511,W0603,W0613,W0621,W0702,W0703,W1401,E1136
 PYLINT_ADDITIONAL_BUILTINS_FOR_ENGINES := supported_languages,language_aliases
 
 include utils/makefile.python