Drop the 'cockpit join progress' needle match

The text we used to get has been replaced with a spinner, which
is difficult and unreliable to match on. This match was only
here to make the test fail a bit faster if it was broken, so
let's just live without it.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/cockpit/join_progress-20191129.json

@@ -1,15 +0,0 @@
-{
-  "area": [
-    {
-      "type": "match",
-      "width": 152,
-      "ypos": 497,
-      "xpos": 340,
-      "height": 14
-    }
-  ],
-  "properties": [],
-  "tags": [
-    "cockpit_join_progress"
-  ]
-}

needles/cockpit/join_progress-cockpit198.json

@@ -1,15 +0,0 @@
-{
-  "area": [
-    {
-      "xpos": 424,
-      "ypos": 477,
-      "height": 14,
-      "width": 152,
-      "type": "match"
-    }
-  ],
-  "properties": [],
-  "tags": [
-    "cockpit_join_progress"
-  ]
-}

needles/cockpit/join_progress.json

@@ -1,15 +0,0 @@
-{
-  "properties": [],
-  "area": [
-    {
-      "xpos": 237,
-      "ypos": 461,
-      "width": 125,
-      "height": 14,
-      "type": "match"
-    }
-  ],
-  "tags": [
-    "cockpit_join_progress"
-  ]
-}

tests/realmd_join_cockpit.pm

@@ -50,9 +50,6 @@ sub run {
     type_string("monkeys123", 4);
     sleep 3;
     assert_and_click "cockpit_join_button";
-    # check we hit the progress screen, so we fail faster if it's
-    # broken
-    assert_screen "cockpit_join_progress";
     # join involves package installs, so it may take some time
     assert_screen "cockpit_join_complete", 300;
     # quit browser to return to console