Do not check if artifact is already installed

The Mender Client used to check if the downloaded artifact was already
installed in the past. However, this check was removed in
[mendersoftware/mender@1fb6223](mendersoftware/mender@1fb6223)
as it prevents the use of the "Force update" option, allowing a device
to take part in the same deployment twice. Today, all the
"already-installed" logic is performed in the backend.

Signed-off-by: Lars Erik Wik <[email protected]>

core/src/mender-client.c

@@ -897,13 +897,6 @@ mender_client_update_work_function(void) {
         goto END;
     }
 
-    /* Check if artifact is already installed (should not occur) */
-    if (!strcmp(artifact_name, mender_client_config.artifact_name)) {
-        mender_log_error("Artifact is already installed");
-        mender_client_publish_deployment_status(id, MENDER_DEPLOYMENT_STATUS_ALREADY_INSTALLED);
-        goto END;
-    }
-
     /* Reset flags */
     mender_client_deployment_needs_set_pending_image = false;
     mender_client_deployment_needs_restart           = false;