fix: update text

Author: sgratzl

themes/delphi/layouts/_default/covidcast_app.html

@@ -12,8 +12,8 @@
   <div class="uk-alert-warning uk-margin-small-top uk-margin-small-bottom" uk-alert>
     <a class="uk-alert-close" uk-close></a>
     <p>
-      We are experiencing problems with out data backend are currently upgrading our systems. Therefore, data are only
-      available till <strong>February 1st, 2021</strong>
+      Due to an issue with our backend, no data newer than <strong>February 1st</strong> is being added to the system.
+      It will take us about a week to address the issue and resume daily updates.
     </p>
   </div>
   <div id="vizbox">