fix changelog entry for --rr (#394)

This is a followup to PR #362.

Author: vcunat

CHANGELOG.md

@@ -18,7 +18,7 @@
 
 - Removed support for Windows
 - Replaced `--gdb` flag with `--gdb-cmd`. The `--gdb-cmd` argument specifies the gdb executable as well as all arguments you wish to pass to gdb at startup, for example `--gdb-cmd "gdb -nx"`. The existing `-g` argument is an alias for `--gdb-cmd`.
-- Removed `--rr` flag. Use `--gdb-cmd rr replay` instead.
+- Removed `--rr` flag. Use `--gdb-cmd "rr replay --"` instead.
 - Removed deprecated and hidden `--hide-gdbgui-upgrades` argument. It will now raise an error.
 
 **Additional Changes**