FetchError: Show a specific message if the error is a TimeoutError.

And add that message and the existing message to messages_en.json;
looks like we forgot to add the existing one.

src/chat/FetchError.js

@@ -5,6 +5,7 @@ import { StyleSheet, View } from 'react-native';
 
 import type { Narrow } from '../types';
 import { Label } from '../common';
+import { TimeoutError } from '../utils/async';
 
 const styles = StyleSheet.create({
   container: {
@@ -28,7 +29,13 @@ export default class FetchError extends PureComponent<Props> {
   render() {
     return (
       <View style={styles.container}>
-        <Label style={styles.text} text="Oops! Something went wrong." />
+        {(() => {
+          if (this.props.error instanceof TimeoutError) {
+            return <Label style={styles.text} text="Request timed out." />;
+          } else {
+            return <Label style={styles.text} text="Oops! Something went wrong." />;
+          }
+        })()}
       </View>
     );
   }

static/translations/messages_en.json

@@ -37,6 +37,8 @@
   "Password": "Password",
   "Why not start the conversation?": "Why not start the conversation?",
   "That conversation doesn't seem to exist.": "That conversation doesn't seem to exist.",
+  "Request timed out.": "Request timed out.",
+  "Oops! Something went wrong.": "Oops! Something went wrong.",
   "Chat": "Chat",
   "Sign in with {method}": "Sign in with {method}",
   "Cannot connect to server": "Cannot connect to server",