Cannot execute JavaScript file

[niccokunzmann]

Presently, the javascript_url parameter should point to a script to be loaded into the OWC instance to allow customization.
However when hosting a script in a github gist, the content type is text/plain and will not reliably be executed.

• make sure scripts with all different content types can be loaded

To reproduce:

https://open-web-calendar.hosted.quelltext.eu/calendar.html?language=de&javascript_url=https://gist.github.com/niccokunzmann/a91d4e8f55609b3106460c7aed1e2753/raw/ab5e9a9a64d65d85b07d2e60df9b94c52a5d7a92/set%2520event%2520height

https://developer.mozilla.org/de/docs/Web/HTTP/Headers/X-Content-Type-Options?utm_source=mozilla&utm_medium=firefox-console-errors&utm_campaign=default

See also:

• Multiline display in month mode #625
• Add JavaScript hook #71