fix(aws): do not print region if it's not defined

plugins/aws/aws.plugin.zsh

@@ -196,9 +196,15 @@ compctl -K _aws_profiles asp acp aws_change_access_key
 
 # AWS prompt
 function aws_prompt_info() {
-  if [[ -z $AWS_REGION && -z $AWS_PROFILE ]];then return; fi
-  region=${AWS_REGION:-${AWS_DEFAULT_REGION:-$AWS_PROFILE_REGION}}
-  echo "${ZSH_THEME_AWS_PROFILE_PREFIX:=<aws:}${AWS_PROFILE}${ZSH_THEME_AWS_PROFILE_SUFFIX:=>} ${ZSH_THEME_AWS_REGION_PREFIX:=<region:}${region}${ZSH_THEME_AWS_REGION_SUFFIX:=>}"
+  local _aws_to_show
+  if [[ -n $AWS_PROFILE ]];then
+    _aws_to_show+="${ZSH_THEME_AWS_PROFILE_PREFIX:=<aws:}${AWS_PROFILE}${ZSH_THEME_AWS_PROFILE_SUFFIX:=>}"
+  fi
+  if [[ -n $AWS_REGION ]]; then
+    [[ -n $AWS_PROFILE ]] && _aws_to_show+=" "
+    _aws_to_show+="${ZSH_THEME_AWS_REGION_PREFIX:=<region:}${region}${ZSH_THEME_AWS_REGION_SUFFIX:=>}"
+  fi
+  echo "$_aws_to_show"
 }
 
 if [[ "$SHOW_AWS_PROMPT" != false && "$RPROMPT" != *'$(aws_prompt_info)'* ]]; then