Filter null comments coming into moderation queues to prevent white screening (#2509)

Wyatt and I are not sure why comments are coming back null, but this should
keep the moderation area from blanking out when it errors handling nulled out
comments crashing the queue.

FIXME tag added with Wyatt/Nick as this is only a patching fix and does
not resolve the underlying issue.

src/core/client/admin/routes/Moderate/Queue/Queue.tsx

@@ -71,26 +71,29 @@ const Queue: FunctionComponent<Props> = ({
         </Flex>
       )}
       <TransitionGroup component={null} appear={false} enter={false} exit>
-        {comments.map(c => (
-          <CSSTransition
-            key={c.id}
-            timeout={400}
-            classNames={{
-              exit: styles.exitTransition,
-              exitActive: styles.exitTransitionActive,
-              exitDone: styles.exitTransitionDone,
-            }}
-          >
-            <ModerateCardContainer
-              settings={settings}
-              viewer={viewer}
-              comment={c}
-              danglingLogic={danglingLogic}
-              showStoryInfo={Boolean(allStories)}
-              onUsernameClicked={onShowUserDrawer}
-            />
-          </CSSTransition>
-        ))}
+        {comments
+          // FIXME (Nick/Wyatt): Investigate why comments are coming back null
+          .filter(c => Boolean(c))
+          .map(c => (
+            <CSSTransition
+              key={c.id}
+              timeout={400}
+              classNames={{
+                exit: styles.exitTransition,
+                exitActive: styles.exitTransitionActive,
+                exitDone: styles.exitTransitionDone,
+              }}
+            >
+              <ModerateCardContainer
+                settings={settings}
+                viewer={viewer}
+                comment={c}
+                danglingLogic={danglingLogic}
+                showStoryInfo={Boolean(allStories)}
+                onUsernameClicked={onShowUserDrawer}
+              />
+            </CSSTransition>
+          ))}
       </TransitionGroup>
       {hasMore && (
         <Flex justifyContent="center">