! Warn if posting would revert the locked/stickied status of a topic when said status changed while you were replying (per #2173)

Signed-off-by: Michael Eshom <oldiesmann@oldiesmann.us>
Merge pull request #2175 from Oldiesmann/release-2.1

! Warn if posting would revert the locked/stickied status of a topic whe...