messagesActions [nfc]: Separate nearOperand-is-null case into early return

NFC because doNarrow's second param defaults to 0, so not passing a
second argument is the same as passing 0 for it.

Also NFC because doNarrow drops that param on the floor.

Author: chrisbobbe

src/message/messagesActions.js

@@ -38,7 +38,12 @@ export const messageLinkPress =
     if (narrow) {
       // This call is OK: `narrow` is truthy, so isNarrowLink(…) was true.
       const nearOperand = getNearOperandFromLink(href, auth.realm);
-      dispatch(doNarrow(narrow, nearOperand ?? 0));
+      if (nearOperand === null) {
+        dispatch(doNarrow(narrow));
+        return;
+      }
+
+      dispatch(doNarrow(narrow, nearOperand));
     } else if (!isUrlOnRealm(href, auth.realm)) {
       openLinkWithUserPreference(href, getGlobalSettings());
     } else {