openapi: Fix minor assertion in curl examples.
openapi: Fix minor assertion in curl examples.

Now, include and exclude configuration
are fetched from openapi data, and only
one type can be encoded for every example.

This removes the need for the assertion to
test if both include and exclude are present
since at a time, only one can be present.

hackerkid/zulip,rht/zulip,punchagan/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,punchagan/zulip,punchagan/zulip,kou/zulip,andersk/zulip,zulip/zulip,zulip/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,andersk/zulip,zulip/zulip,eeshangarg/zulip,hackerkid/zulip,kou/zulip,rht/zulip,hackerkid/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,punchagan/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,rht/zulip,hackerkid/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,hackerkid/zulip,andersk/zulip,zulip/zulip,rht/zulip,punchagan/zulip,rht/zulip,andersk/zulip,andersk/zulip,kou/zulip,zulip/zulip,andersk/zulip,punchagan/zulip