fix url parameter organizer replacing first dropdown item

add organizer at the end instead of during filtering. Probably not the
optimal way to do this but works for now.

web/src/components/events/EventContainer.tsx

@@ -84,13 +84,22 @@ export const EventContainer = ({
       .filter((x) => typeof x === "string" && x !== "")
   );
   const filterableOrganizers = uniqueOrganizers
-    .map((slug) =>
-      eventOrganizers.find(
-        (haystack) => haystack.slug === slug || haystack.slug == organizer
-      )
-    )
+    .map((slug) => eventOrganizers.find((haystack) => haystack.slug === slug))
     .filter((x) => x !== undefined) as EventOrganizer[];
 
+  // If an organizer is selected that's not in the upcoming list, add it
+  if (
+    organizer &&
+    !filterableOrganizers.some((org) => org.slug === organizer)
+  ) {
+    const selectedOrganizer = eventOrganizers.find(
+      (org) => org.slug === organizer,
+    );
+    if (selectedOrganizer) {
+      filterableOrganizers.push(selectedOrganizer);
+    }
+  }
+
   /* Reset organizer if slug is invalid */
   useEffect(() => {
     if (!eventOrganizers.find((haystack) => haystack.slug === organizer)) {