fix: correct issue with clearing global domains

Also update tests

plugins/domains/functions

@@ -170,7 +170,7 @@ domains_add_global() {
     ) -eq 0 ]]; then
       dokku_log_info1 "Skipping: $DOMAIN already added"
     else
-      sed -i -e "\$a\\$DOMAIN" "$GLOBAL_VHOST_PATH"
+      grep -qxF "$DOMAIN" "$GLOBAL_VHOST_PATH" || echo "$DOMAIN" >>"$GLOBAL_VHOST_PATH"
       dokku_log_info1 "Added $DOMAIN"
     fi
   done

plugins/domains/subcommands/clear-global

@@ -9,7 +9,8 @@ domains_clear_global_cmd() {
   local cmd="domains:clear-global"
   shift 1
 
+  dokku_log_info1_quiet "Clearing global domains"
   domains_clear_global "$@"
 }
 
-domains_add_global_cmd "$@"
+domains_clear_global_cmd "$@"

tests/unit/20_domains.bats

@@ -253,6 +253,7 @@ teardown() {
   run /bin/bash -c "dokku domains:clear-global"
   echo "output: $output"
   echo "status: $status"
+  assert_success
   refute_line "global.dokku.invalid"
   refute_line "global.dokku.me"
 }