Bug 1548742 Spelling error in console warning: "Unkown category". r=janerik

Differential Revision: https://phabricator.services.mozilla.com/D29881

--HG--
extra : moz-landing-system : lando

toolkit/components/telemetry/core/TelemetryEvent.cpp

@@ -1344,7 +1344,10 @@ void TelemetryEvent::SetEventRecordingEnabled(const nsACString& category,
   if (!gCategoryNames.Contains(category)) {
     LogToBrowserConsole(
         nsIScriptError::warningFlag,
-        NS_LITERAL_STRING("Unkown category for SetEventRecordingEnabled."));
+        NS_ConvertUTF8toUTF16(
+            NS_LITERAL_CSTRING(
+                "Unknown category for SetEventRecordingEnabled: ") +
+            category));
     return;
   }