[fix] return correct plugin path

closes #1021

searx/templates/oscar/base.html

@@ -103,7 +103,7 @@
             data-infinite-scroll="{% if infinite_scroll %}true{% else %}false{% endif %}"
             data-translations="{{ translations }}"></script>
     {% for script in scripts %}
-    {{""}}<script src="{{ url_for('static', filename=script) }}"></script>
+    {{""}}<script src="{{ url_for('plugins', filename=script) }}"></script>
     {% endfor %}
     <noscript>
       <style>

searx/webapp.py

@@ -355,6 +355,12 @@ def custom_url_for(endpoint: str, override_theme: Optional[str] = None, **values
             file_hash = static_files.get(filename_with_theme)
             if file_hash:
                 suffix = "?" + file_hash
+    if endpoint == 'plugins' and values.get('filename'):
+        endpoint = 'static'
+        if get_setting('ui.static_use_hash', False):
+            file_hash = static_files.get(values['filename'])
+            if file_hash:
+                suffix = "?" + file_hash
     if endpoint == 'info' and 'locale' not in values:
         locale = request.preferences.get_value('locale')
         if _INFO_PAGES.get_page(values['pagename'], locale) is None: