Handle emergency console entry with no password

This happens on ARM disk images.

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

lib/installedtest.pm

@@ -33,9 +33,12 @@ sub root_console {
 sub post_fail_hook {
     my $self = shift;
 
-    if (check_screen 'emergency_rescue', 3) {
+    if (check_screen ['emergency_rescue', 'emergency_rescue_nopassword'], 3) {
+        if (match_has_tag 'emergency_rescue') {
             my $password = get_var("ROOT_PASSWORD", "weakpassword");
-        type_string "$password\n";
+            type_string "$password";
+        }
+        send_key 'ret';
         # bring up network so we can upload logs
         assert_script_run "dhclient";
     }

needles/console/emergency_rescue_nopassword-20201028.json

@@ -0,0 +1,16 @@
+{
+  "area": [
+    {
+      "height": 16,
+      "width": 216,
+      "type": "match",
+      "ypos": 736,
+      "xpos": 0
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "LANGUAGE-english",
+    "emergency_rescue_nopassword"
+  ]
+}