Remove trailing semicolon to allow appending to PROMPT_COMMANDS

[brandonweeks]

Before:

$ source bash-preexec.sh
$ PROMPT_COMMAND="$PROMPT_COMMAND; true"
bash: PROMPT_COMMAND: line 3: syntax error near unexpected token `;;'
bash: PROMPT_COMMAND: line 3: `__bp_precmd_invoke_cmd;  __bp_interactive_mode;; true'
$ 

After:

$ source bash-preexec.sh
$ PROMPT_COMMAND="$PROMPT_COMMAND; true"
$ declare -p PROMPT_COMMAND
declare -- PROMPT_COMMAND="__bp_precmd_invoke_cmd;  __bp_interactive_mode; true"
$ 

[rcaloras]

This one is more of a design decision right? I feel like you could argue that we should still end PROMPT_COMMAND with a semicolon and then just append without it.

[rcaloras]

👍 Putting it through regardless. Thanks for all the PRs!

@brandonweeks ⭐ 🥇