NPM proxy repo does not honor remote url configuration change

1. Create an npm proxy pointing to remote url https://registry.npmjs.org/
2. Retrieve lodash. Verify it was downloaded to the proxy. Then delete the asset from the proxy.
3. Change the proxy configuration to an invalid remote URL

2019-11-21 16:49:54,448-0800 INFO [qtp1908233178-3484] admin org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl - Updating repository: npm-proxy -> Configuration{repositoryName='npm-proxy', recipeName='npm-proxy', attributes={proxy=

{remoteUrl=https://invalidservername.org/, contentMaxAge=1440.0, metadataMaxAge=1440.0}

, httpclient={blocked=false, autoBlock=true, connection={useTrustStore=false}}, storage=

{blobStoreName=default, strictContentTypeValidation=true}

, negativeCache=

{enabled=true, timeToLive=1440.0}

}}

4. Clear local npm cache and retrieve lodash again. The nexus.log shows a connection established to registry.npmjs.org

2019-11-21 16:50:18,230-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.impl.execchain.MainClientExec - Opening connection

{s}

->https://registry.npmjs.org:443
2019-11-21 16:50:18,232-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.impl.conn.DefaultHttpClientConnectionOperator - Connecting to registry.npmjs.org/104.16.26.35:443
2019-11-21 16:50:18,232-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.conn.ssl.SSLConnectionSocketFactory - Connecting socket to registry.npmjs.org/104.16.26.35:443 with timeout 20000

2019-11-21 16:50:18,261-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.impl.execchain.MainClientExec - Executing request GET /lodash/-/lodash-4.17.15.tgz HTTP/1.1
2019-11-21 16:50:18,261-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.impl.execchain.MainClientExec - Target auth state: UNCHALLENGED
2019-11-21 16:50:18,262-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.impl.execchain.MainClientExec - Proxy auth state: UNCHALLENGED
2019-11-21 16:50:18,262-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.headers - http-outgoing-106 >> GET /lodash/-/lodash-4.17.15.tgz HTTP/1.1
2019-11-21 16:50:18,262-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.headers - http-outgoing-106 >> Host: registry.npmjs.org
2019-11-21 16:50:18,263-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.headers - http-outgoing-106 >> Connection: Keep-Alive
2019-11-21 16:50:18,263-0800 DEBUG [qtp1908233178-3500] *UNKNOWN org.apache.http.headers - http-outgoing-106 >> User-Agent: Nexus/3.19.0-01 (PRO; Mac OS X; 10.13.6; x86_64; 1.8.0_192)

5. Browse the npm proxy and verify that lodash was retrieved again.

Expected:
retrieving lodash would fail when the proxy configuration changed to an invalid remote url

Actual:
proxy used the old remote url