make removeEmptyString fn as helper fn

lnbits/app.py

@@ -26,6 +26,7 @@ from .helpers import (
     get_css_vendored,
     get_js_vendored,
     get_valid_extensions,
+    removeEmptyString,
     template_renderer,
     url_for_vendored,
 )
@@ -112,9 +113,6 @@ def check_settings(app: FastAPI):
     @app.on_event("startup")
     async def check_settings_admin():
 
-        def removeEmptyString(arr):
-            return list(filter(None, arr))
-
         while True:
             admin_set = await get_admin_settings()
             if admin_set :