Improve and reuse language keys

src/lang/en.json

@@ -173,6 +173,7 @@
     "Avg. Response": "Avg. Response",
     "Entry Page": "Entry Page",
     "statusPageNothing": "Nothing here, please add a group or a monitor.",
+    "statusPageRefreshIn": "Refresh in: {0}",
     "No Services": "No Services",
     "All Systems Operational": "All Systems Operational",
     "Partially Degraded Service": "Partially Degraded Service",

src/pages/StatusPage.vue

@@ -308,8 +308,8 @@
                 </p>
 
                 <div class="refresh-info mb-2">
-                    <div>{{ $t("last update") }}: <date-time :value="lastUpdateTime" /></div>
-                    <div>{{ $t("refresh in") }}: {{ updateCountdownText }}</div>
+                    <div>{{ $t("Last Updated") }}: <date-time :value="lastUpdateTime" /></div>
+                    <div>{{ $tc("statusPageRefreshIn", [ updateCountdownText]) }}</div>
                 </div>
             </footer>
         </div>