UI: Rename 'ready' to 'needed' in tasks summary

Ready tasks were shown as 'needed' since Iaafdb57a, but
unintentionally updated to 'ready' in I383291e3.

Change-Id: Id1685f9e34dc1fa827153b7a80dcc85237057f09

gr-task-plugin/gr-task-summary_html.js

diff --git a/gr-task-plugin/gr-task-summary_html.js b/gr-task-plugin/gr-task-summary_html.js
index 577f8ce..9da3c7c 100644
--- a/gr-task-plugin/gr-task-summary_html.js
+++ b/gr-task-plugin/gr-task-summary_html.js
@@ -76,7 +76,7 @@
             <gr-task-chip chip_style="fail" hidden$="[[!fail_count]]">[[fail_count]] blocked</gr-task-chip>
             <gr-task-chip chip_style="invalid" hidden$="[[!invalid_count]]">[[invalid_count]] invalid</gr-task-chip>
             <gr-task-chip chip_style="duplicate" hidden$="[[!duplicate_count]]">[[duplicate_count]] duplicate</gr-task-chip>
-            <gr-task-chip chip_style="ready" hidden$="[[!ready_count]]">[[ready_count]] ready</gr-task-chip>
+            <gr-task-chip chip_style="ready" hidden$="[[!ready_count]]">[[ready_count]] needed</gr-task-chip>
             <gr-task-chip chip_style="waiting" hidden$="[[!waiting_count]]">[[waiting_count]] waiting</gr-task-chip>
             <gr-task-chip chip_style="success" hidden$="[[!pass_count]]">[[pass_count]] passed</gr-task-chip>
         </template>