Fix Frozen String Error in Commercials Controller
Fix Frozen String Error in Commercials Controller

`errors_text` is a frozen string, so `<<` leads to an exception when trying to generate the error message.

https://sentry.cs10.org/share/issue/7867fdaf8eba4387ae2789fd5f1cff3b/
if you want a production example. :)
differentreality/osem,openSUSE/osem,openSUSE/osem,hennevogel/osem,hennevogel/osem,hennevogel/osem,SeaGL/osem,hennevogel/osem,openSUSE/osem,differentreality/osem,AndrewKvalheim/osem,SeaGL/osem,AndrewKvalheim/osem,AndrewKvalheim/osem,differentreality/osem,differentreality/osem,SeaGL/osem