WASX7023E: Error creating "SOAP" connection to host "localhost" after enabling TLS 1.2

On the back of my earlier post: -

JSSL0080E: javax.net.ssl.SSLHandshakeException - The client and server could not negotiate the desired level of security 

having changed my WAS cell to only support TLS 1.2, I then realised that the WSAdmin client would no longer work.

/opt/ibm/ODM/WebSphereProfiles/ODMCell1Dmgr01/bin/wsadmin.sh -lang jython -hostname `hostname`.uk.ibm.com -port 13503

WASX7023E: Error creating "SOAP" connection to host "localhost"; exception information: com.ibm.websphere.management.exception.ConnectorNotAvailableException: [SOAPException: faultCode=SOAP-ENV:Client; msg=Error parsing HTTP status line "": java.util.NoSuchElementException; targetException=java.lang.IllegalArgumentException: Error parsing HTTP status line "": java.util.NoSuchElementException]

WASX7213I: This scripting client is not connected to a server process; please refer to the log file /opt/ibm/ODM/WebSphereProfiles/ODMCell1Dmgr01/logs/wsadmin.traceout for additional information.

WASX8011W: AdminTask object is not available.

WASX7411W: Ignoring the following provided option: [-hostname, wasdemo.uk.ibm.com]

WASX7031I: For help, enter: "print Help.help()"
This time I knew where to look, and what to change.

Sure enough, I checked out: -

/opt/ibm/ODM/WebSphereProfiles/ODMCell1Dmgr01/properties/ssl.client.props

and found: -

com.ibm.ssl.protocol=SSL_TLS

where I should've seen: -

com.ibm.ssl.protocol=TLSv1.2

Once I amended the file, all was well.

I'm guessing, but haven't yet checked, that I could've simply overridden the property file with a command-line parameter such as -D com.ibm.ssl.protocol=TLSv1.2 

Something to check here: -

Using the Administration Thin Client