popups: Make senventh column of date picker visible (MR 45)

Closes https://gitlab.com/postmarketOS/mobile-config-firefox/-/issues/63

src/userChrome/popups.css

@@ -35,11 +35,13 @@
     }
 
     /* fix flickering of the protections, permissions,
-     * widget overflow and identity popups */
+     * widget overflow and identity popups, make seventh
+     * column of date picker visible */
     #protections-popup,
     #permission-popup,
     #widget-overflow,
-    #identity-popup {
+    #identity-popup,
+    #date-picker {
         max-width: 100vw !important;
     }