share-to [nfc]: Convert a TODO-3918 comment to a TODO-server

This is (as the comment already says) blocked behind a minimum-server
upgrade, so it's not really actionable on its own.  Instead, connect
the TODO to that upgrade.

src/sharing/ShareWrapper.js

@@ -25,7 +25,7 @@ import { IconAttachment, IconCancel } from '../common/Icons';
 
 type SendTo =
   | {| type: 'pm', selectedRecipients: $ReadOnlyArray<UserId> |}
-  // TODO(#3918): Drop streamName.  Used below for sending.
+  // TODO(server-2.0): Drop streamName (#3918).  Used below for sending.
   | {| type: 'stream', streamName: string, streamId: number, topic: string |};
 
 const styles = createStyleSheet({
@@ -176,7 +176,7 @@ class ShareWrapperInner extends React.Component<Props, State> {
             content: messageToSend,
             type: 'stream',
             subject: sendTo.topic || apiConstants.NO_TOPIC_TOPIC,
-            // TODO(server-2.0): switch to numeric stream ID, not name;
+            // TODO(server-2.0): switch to numeric stream ID (#3918), not name;
             //   then drop streamName from SendTo
             to: sendTo.streamName,
           };