Check for rabbitmqctl using `[ -x ]` and not `which` in autocompletion

scripts/bash_autocomplete.sh

@@ -1,9 +1,11 @@
 _rabbitmqctl_complete() {
+    if [ -x /usr/lib/rabbitmq/bin/rabbitmqctl ]; then
         COMPREPLY=()
         local LANG=en_US.UTF-8
         local word="${COMP_WORDS[COMP_CWORD]}"
         local completions="$(export LANG=en_US.UTF-8; export LC_CTYPE=en_US.UTF-8; /usr/lib/rabbitmq/bin/rabbitmqctl --auto-complete $COMP_LINE)"
         COMPREPLY=( $(compgen -W "$completions" -- "$word") )
+    fi
 }
 
 complete -f -F _rabbitmqctl_complete rabbitmqctl

scripts/rabbitmqctl-autocomplete.sh

@@ -1,5 +1,3 @@
-if which rabbitmqctl > /dev/null; then
-    if [ -n "$BASH_VERSION" ]; then
+if [ -n "$BASH_VERSION" ]; then
     . /usr/lib/rabbitmq/autocomplete/bash_autocomplete.sh
-    fi
 fi

scripts/zsh_autocomplete.sh

@@ -1,10 +1,12 @@
 _rabbitmqctl_complete() {
+    if [ -x /usr/lib/rabbitmq/bin/rabbitmqctl ]; then
         local word completions a
         local LANG=en_US.UTF-8
         read -cl a
         word="$1"
         completions="$(export LANG=en_US.UTF-8; export LC_CTYPE=en_US.UTF-8; /usr/lib/rabbitmq/bin/rabbitmqctl --auto-complete ${=a})"
         reply=( "${(ps:\n:)completions}" )
+    fi
 }
 
 compctl -f -K _rabbitmqctl_complete rabbitmqctl