[mod] UX: flush flag icon to right in language select option values

If the flag icon is first, it prevents easily searching the select list on the
keyboard.  By moving the icon fully to the right, this will enable a user to
search the select list.

Closes: https://github.com/searxng/searxng/issues/3645

searx/templates/simple/preferences/language.html

@@ -13,9 +13,9 @@
       {% for sxng_tag,lang_name,country_name,english_name,flag in sxng_locales | sort(attribute=1) -%}
         <option value="{{ sxng_tag }}"
                 {%- if sxng_tag == current_language %} selected="selected" {%- endif -%}>
-                {%- if flag -%}{{ flag }} {% endif -%}
                 {{ lang_name }}{%- if country_name -%}-{{ country_name }}{%- endif -%}
-                {{- ' ' -}}[{{sxng_tag}}]{{- '' -}}
+                {{- ' ' -}}[{{sxng_tag}}]{{- ' ' -}}
+                {%- if flag -%}{{ flag }}{%- endif -%}
         </option>
       {%- endfor -%}
     </select>{{- '' -}}