Updating a design doc view map function does not take effect

[raghusarangapani]

The issue was originally reported against android:
https://github.com/couchbase/couchbase-lite-android/issues/1139

Test case:

1. Add 10 docs to the client with content
2. Add 5 docs to the client without content
3. Create design doc version 1 to fetch doc._id, doc._rev for docs with content
4. Run a query and check for 10 expected docs with design doc version 1
5. Update design doc to version 2 to fetch doc._id, doc._rev for docs with no content
6. Run a query and check for 5 expected docs with design doc version 2
   -> Even though design doc is updated to version 2, the second query will use design doc 1 and return 10 docs instead of 5

Steps to reproduce:

pytest -k test_design_doc_update --liteserv-platform=macosx --liteserv-version=1.4.0-3 --liteserv-host=localhost --liteserv-port=59840 --liteserv-storage-engine=SQLite --sync-gateway-version=1.4.2-368 --sync-gateway-mode=cc --server-version=5.0.0-2873 testsuites/listener/shared/client_sg/

---

• Version: 1.4.0-3
• Client OS: mac
• Server: SG 1.4.2-368