SPNEGO always canonicalizes host names, Option to pick behavior would be welcome

**Zoltan Farkas** ([Bug 60696](https://bz.apache.org/bugzilla//show_bug.cgi?id=60696&redirect=false)):
At:

https://github.com/apache/jmeter/blob/c616f4f84d11812febbf442806b90b02c306fe0c/src/protocol/http/org/apache/jmeter/protocol/http/control/AuthManager.java#L474

SPNegoSchemeFactory is created like:

new SPNegoSchemeFactory(isStripPort(url)));

the scheme factory has an alternate constructor (https://github.com/apache/httpclient/blob/4.5.x/httpclient/src/main/java/org/apache/http/impl/auth/SPNegoSchemeFactory.java#L53) that allows to pick canonicalization behavior for the host name:

/**
* @since 4.4
*/
public SPNegoSchemeFactory(final boolean stripPort, final boolean useCanonicalHostname) {

Unfortunately for certain use cases where we have a load balancer serving multiple names mapped to the same IP address the canonicalization breaks authentication for us by generating a incorrect SPN.

It would be helpful to be able to control this behavior in JMeter either via UI or config.

Severity: normal
OS: Mac OS X 10.1

Start in src/protocol/http/org/apache/jmeter/protocol/http/control/AuthManager.java around line 474 and compare the available SPNegoSchemeFactory constructors in Apache HttpClient 4.5.x. Trace how authentication settings are exposed through JMeter's UI or configuration, then verify that the selected canonicalization behavior works for hosts behind a load balancer without breaking existing behavior.

Written by the indexing model from the issue text.