Allow multiple basic auth accounts to be configured

roles/searx/templates/upstream.json.j2

@@ -32,10 +32,15 @@
             "providers": { 
                 "http_basic": {
                     "accounts": [
+{% for user in searx_authentication %}
                         {
-                            "username": "{{ searx_authentication.username }}",
-                            "password": "{{ searx_authentication.password }}"
+                            "username": "{{ user.username }}",
+                            "password": "{{ user.password }}"
                         }
+                        {% if not loop.last %}
+                        ,
+                        {% endif %}
+{% endfor %}
                     ]
                 }
             }