Update some Cockpit button needles for 217

Seems like text rendering on buttons changed a bit.

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

needles/cockpit/cockpit_updates_dnf_install-cockpit217-20200415.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "xpos": 336,
+      "width": 49,
+      "height": 17,
+      "type": "match",
+      "ypos": 329
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "cockpit_updates_dnf_install"
+  ]
+}

needles/cockpit/join_button-cockpit217-20200415.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "type": "match",
+      "height": 18,
+      "ypos": 500,
+      "xpos": 344,
+      "width": 31
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "cockpit_join_button"
+  ]
+}