Submitting a message without content will send a empty message

### OS/platform OpenSUSE ### Emacs version and provenance OpenSUSE Repos ### Emacs command emacs --fg-daemon ### Emacs frame type Gui ### Ement package version and provenance latest-master ### Actions taken - Default settings 1. Enter a room 2. Press ENTER 3. Press Enter again 4. Empty message ### Observed results A message was send. ### Expected results No message. ### Backtrace ```elisp ``` ### Etc. _No response_