Fix sending chat messages

Fixes https://gitlab.com/soapbox-pub/soapbox/-/issues/1752

src/features/chats/components/chat.tsx

@@ -96,7 +96,7 @@ const Chat: React.FC<ChatInterface> = ({ chat, inputRef, className }) => {
     if (!isSubmitDisabled && !createChatMessage.isPending) {
       submitMessage();
 
-      if (!chat.accepted) {
+      if (chat.accepted === false) {
         acceptChat.mutate();
       }
     }

src/queries/chats.ts

@@ -294,8 +294,7 @@ const useChatActions = (chatId: string) => {
     onError: (_error: any, variables, context: any) => {
       queryClient.setQueryData(['chats', 'messages', variables.chatId], context.prevChatMessages);
     },
-    onSuccess: async (response, variables, context) => {
-      const data = await response.json();
+    onSuccess: (data, variables, context) => {
       const nextChat = { ...chat, last_message: data };
       updatePageItem(ChatKeys.chatSearch(), nextChat, (o, n) => o.id === n.id);
       updatePageItem(